ArmchairBuilder > Resources > Home Additions

Home Additions


Tips for Home Additions 

A home addition can be a great way to add space to accomodate a growing family.  If you’ve already finished your basement, you may have started investigatiing home additions.  If you haven’t yet decided to take the plunge, check out our post titled What Does it Cost to Add Living Space? to help with the decision making process.

Here we will discuss important items that are considered by professional contractors when planning new home additions.  Even if you decide not to go the owner builder route for your new additions, you will want to go through these pre-planning tips to ensure your project is built correctly.  Discussion topics will include the following important items when you add on to your home…

  • Blend Addition into Design of Existing Home

  • Check Zoning Requirements at your Local Zoning Department

  • Check with you Homeowner’s Association for Requirements

  • Determine How you will Finance the Project to Add on to Your Home

  • Make Sure  New Roof and Floor lines Match Existing Elevations

  • Protect Existing Home from the Elements

  • Check HVAC for Proper Sizing

  • Insurance:  Discuss Project with Your Homeowner’s Insurance Company

  • Talk to Your Neighbors before any home additions are started

These are all very important items to consider prior to starting construction on a home addition.  


Home Additions: How to Finance?

We have a whole host of financing options available for home additions.  Each option has it’s pros and cons.  So which is best for your situation?  Here we will discuss the main options available and give you the major points to consider for each.


Cash:  If you have the cash sitting idle in the bank, either in a savings or money market account, now is a good time to use it to add on to your home.  The rates currently paid on a typical savings account are paltry…somewhere from one percent to  darn near nothing.  If you have the money, it makes no sense to let it continue to make almost nothing so you can turn around and pay five to ten percent to use someone else’s money.  Of course this assumes you will still have a six month emergency reserve account…don’t use this up.  If you can go the cash route, you save on fees, closing costs, appraisals, inspections…etc. when you add on to your home.

Home Equity Loan:  A home equity loan can be a great way to finance new home additions. These offer the tax benefits of conventional mortgages without the closing costs.  The bank gives you the entire loan amount up front and you will pay the balance off over fifteen to thirty years.  Your monthly payments can be fixed as most of these have a fixed interest rate.  The major drawback to the home equity loan is the interest rates are slightly higher than those for conventional mortgages.  Of course, you need equity in your home to be eligible for this loan type for financing your project to add on to your home.

Home Equity Line of Credit:  Also called a HELOC, this method of financing can be a great way to finance home additions if there is equity in the home.  These work similarly to a credit card in that the banks agree to lend you up to a certain amount of money and you draw the money against the line of credit as you wish.  There are no closing costs and the interest rates are adjustable, with many tied to the prime rate.  Many of these require repayment within eight to ten years.  Pay close attention when comparing this type of loan to a traditional home equity loan.  The APR (annual percentage rate) for a home equity line of credit is based on the periodic interest rate alone and does not include points or other charges like a home equity loan does.

Title 1 Home Improvement:  The government provides private lenders with insurance to provide loans up to $25k for terms as long as twenty years.  If the loan is over $7500, it must be secured by a mortgage or dead of trust on the property.  This is one of the easier loans to qualify for as it is based on your ability to repay the loan and can be obtained in a few days.  So, it can be a good way to finance home additions.  This financing method is owner builder friendly. For more information on the Title 1 loan,check out this HUD site.

No matter what loan type you are considering for your project to add on to your home, your chances of being accepted will be greatly improved if you have the following items in place prior to applying…

  • Low debt-to-income ratio

  • High credit score

  • Solid employment history

  • Equity in your home

Financing is one of the important items to consider before planning any home additions.  To see the rest of your essential pre-planning list, go to our previous post… Tips to Add on to Your Home.




Home Additions: Making the New Look...Old

Have you ever driven by a home and thought to yourself…what were they thinking?  There’s nothing worse than looking at a home and being able to distinguish each addition that was built.  The best renovations blend the new in with the old so that everything appears to have been built at the same time.  So how do you accomplish this with new home additions?

First and foremost, make sure your new architectural design matches the old.  Meaning, if your home is a traditional colonial, don’t put a modern addition onto your home.  Or if you have an english tudor, don’t design your new project with a craftsman styling.  If you really want your home to change style altogether, you should change the look of the old to match the new.  When you add on to your home, you want the value to increase and the best way to accomplish that is by making the old match the new.

If we are going to create an addition that looks like it has always been there, we also need to carefully consider the materials we use.  This is easier said than done.  One of the biggest challenges on any renovation or addition is making the new materials match the old.  Even if the existing material type is still available, the fading caused by the sun on the existing material can make color matching impossible on home additions.  

The other issue you contend with when you add on to your home are differing dye lots. Manufacturers have production runs of a given product before they switch over to another color or product type.  In different production runs there can be significant differences in color.  If you want all of the colors and materials to blend exactly when you add on to your home, the easiest way is to replace the entire roof (if it’s asphalt).  Wall cladding should be chosen carefully to avoid mismatch.  Sometimes a different material can be used (like stone for example) that will look good with the old design and will avoid the color differences associated with using the same material.  If you have a painted siding, take a piece of the existing siding down to the hardware store to scan the color in for a computer match.  Even with the computer match, don’t expect the colors to be exact.

If you want to see some home additions that went wrong, check out the bottom of this article at OldHouseOnline titled What Not to Do.  You want to add space and value when you add on to your home...not eyesores and headaches.



Home Additions:  Avoid the Words... "Tear it down"

There are a couple phrases we never want to hear after we complete the project to add on to your home.  The first is…you need a variance.  The second is…tear it down.  So how do we deal with the “V” word and how do we avoid ever having to take down home additions?

If you follow the rules and go to your local zoning department prior to starting your new building projects, you will find out exactly what is needed to comply with your municipality’s zoning requirements.  Zoning rules are put in place so there is order in the neighborhood.  If you had a home close to the ocean with an ocean view, you wouldn’t want your neighbor to put a four story addition on his home that blocks you.  You also probably wouldn’t want your next door neighbors to build home additions that come right up to the lot line next to your home.

How could the zoning rules affect you as an owner builder wanting to add on to your home?  The zoning will affect what you can build and where you can build it.  Some examples of these are as follows…

  • Setback requirements from street, side lot lines, and rear lot lines.  These lines form what builders call a building envelope…the area on your property in which you can build or add on to your home (See the diagram above)

  • Height requirements:  Most municipalities have a maximum height requirement for residential structures.

  • Types of buildings:  The zoning maps that local municipalities have were created to organize development.  You wouldn’t want to live next to an industrial plant or an office building that creates traffic.  So, if you're thinking you will add on to your home to add space for your new business…you will want to check the zoning first.  They may not allow it depending on the types of activities will be going on in the new space as well as the number of workers present.


Some people will tell you to act first and ask questions later.  Meaning, complete your home additions and then see how it goes.  After all, you can just play dumb and say you are an owner builder and didn’t know rules existed that governed what could be built and where, right?  As a builder, I can tell you this is extremely dangerous thinking.  If you neglect to follow the zoning rules, at a minimum you will have to deal with your local zoning department which could lead to any number of outcomes….the worst being an order to tear down the new structure.  Another worst case scenario would be your neighbor sues you for the affect your new project supposedly has on their property value.  Depending on the location of your new project, if you took away a view, the damage could potentially be valued in the hundreds of thousands of dollars (if not millions).

If you do take your project plans into the zoning department and the rules keep you from making any home additions, you have the option of going in for a variance.  A variance is given when the municipality decides that no harm will be done if your project is built even if it doesn’t conform to the rules.  As a builder, I have received variances for structures that encroach over a set back line by a few feet.  These structures included garages, decks and even homes.  Each municipality is different, but to obtain a variance your new project to add on to your home is typically reviewed by the zoning board and the proposed change is communicated to the public to make sure nobody objects.  Before you go to the time and expense to submit for a variance, you may want to ask your local zoning group what your chances are for getting approval.  They may have had the same issue come up recently.

Another group you will want to consult prior to beginning your new project to add on to your home is the homeowner’s association in your community (if you have one).  They typically have covenants and restrictions that serve to protect the property values in the neighborhood and can dictate size, style, materials, and colors of projects within the community.

So do yourself a favor and make sure you check with your local zoning department and homeowner’s association prior to starting any new home additions.  



Home Additions: Make Sure Your Existing/New Roof & Floors Line Up

18087324_0bfcb0289a.jpgWhen you add on to your home, it is critical to put the time and effort into making sure your new floor and roof line up with the existing floor and roof.  This sounds obvious and simple but based on the number of homes I have seen with one or both of these screwed up, I thought I would mention it for your pre-planning checklist.  If your new addition enlarges an existing room, you will need the floor to be one level as it extends out into the new space.  As for the roof lines…it’s partially about how the house looks and partially about avoiding roof leaks.  If the roof planes come close to matching up, but are slightly off, it will look strange and can leak.  If your new design doesn’t tie two roof planes together you may have other issues to consider.  For example, if you add on to your home and the new roof framing extends out over your existing roof, your architect will need to determine whether the existing roof can support the new structure.  Your architect should also carefully consider the new roof design to make certain you aren’t creating any potential leak areas.

As always, the goal at is to provide professional home building guidance without getting too technical.  Therefore, we have avoided the thesis on this subject…we could talk all day about it and provide enough diagrams to make you go blind. Instead, we have given you the basic info you need to be able to manage the contractors on your site.  Remember, we are about teaching you to manage the project as the general contractor…not do the actual work.

Who Can Help Me Make Sure They Line Up? There are five people that are critical to making sure your new addition is built so everything lines up.  Your architect designs the plan and includes a cross section based on the materials you will be using to add on to your home.  So, make sure you don’t change materials after you give them to your architect.  Say for example you originally were going with 2×10 floor joists but now you will be using a manufactured I-joist product.  The difference in joist depth will affect your cross section and ultimately your foundation excavation depth.  

Your architect’s cross section should take into consideration the existing home and the elevation of the floors and the roofs (so she will need to make a field visit out to your home).  It’s helpful to have your architect put a dig depth on the plan from a fixed reference point on the project…say the first floor of the existing home.  This will help your excavation contractor determine how deep to dig for the footing.  Make sure you confirm whether the footing will be trenched or partially trenched by the foundation contractor and communicate this to your architect.  Any trenching that will be done by the foundation contractor will decrease the depth of the excavation.

You will also want to have your roof truss provider discuss the truss dimensions (heel height, pitch and span) with your architect to make sure the roofs will line up (check out this site for a drawing showing heel height).  The last critical person in making sure your roof and floors line up when you add on to your home is the rough carpenter subcontractor.  He will follow your architect’s plans and can make minor adjustments in the field if actual dimensions vary.

With proper planning and communication, your new home additions will be built with the same quality you would get from a professional general contrator.

New addition photo above provided by Orbital Joe




Home Additions: Protect Your Existing Home While Building


You’ve decided to add on to your home as an owner-builder to add valuable space.  Once your new home additions are complete, your family room and kitchen will open up into the large, new space that your family will enjoy for years to come.  Your new construction project will go on for several months so how do you protect your existing home from the rain, snow, and cold while building? How do you keep the dust and noise out that comes along with the construction activity when you add on to your home?

Leave Existing Structure Intact When Building Home Additions: By leaving the existing structure of your home intact for as long as possible, you prevent water and dust intrusion into your home.  Your carpenter should be able to strategically cut siding where necessary to tie the new walls into the existing walls.  Take a look at the picture of the new home addition above.  They have kept the siding and roof in place while building the new structure.  It’s also a good idea to leave windows and doors in the old structure…even if they will be eventually removed.  This helps keep out all kinds of bad byproducts associated with construction including water, cold air, dust, noise…etc.  Any walls that you must open up, you can protect with a good quality housewrap or visqueen.  If your roof planes will line up (with no overlay), you should be able to build your new roof deck right under the old shingle overhang.  Then your roofer can remove old shingles as necessary to tie the new section into the old.  If your new addition requires building a gable on top of your existing roof, you will want to coordinate carefully this work with the weather, roofer, and carpenter.  Tarps help keep water out but they aren’t bullet proof.

Choose Your Start Date Wisely: I’m a big believer in managing what I have control over.  So, if I’m planning on doing any major construction work on my home, I wait until the good weather months.  If I can choose when to start my project, why would I choose the cold or wet months?  If I do, I’m making my life more difficult than it needs to be.  Of course anything can be done.  Building in cold weather is done all the time.  However, it will take more time and cost more money.  Building in the winter requires admixtures, hot water, and blankets for concrete, temporary heat for drywall, tarps and heat for exterior masonry…etc.  And there are some things you won’t want to do outside in the freezing winter months including pouring exterior flatwork, painting, and landscaping.  Being in complete control is one of the best reasons to act as the general contractor when you add on to your home.  For more reasons to take on this role, check out our video Why Build My Own Home?

Use Plastic Between Old and New: Once your rough carpenter does get to the point where he needs to cut into your existing home, make sure you seal up with plastic sheeting between the old and the new.  This will help keep some of the dust out of your existing home.  It's going to take some time to add on to your home, so plan on taking the time to seal up between the old and new.

Put on Your Headphones: Unfortunately, there’s not much you can do about the noise when you add on to your home.  If you have followed my advice above and left the existing structure intact as long as possible, you should minimize the noise in your existing home.  However, the noise can’t be eliminated completely and it will get louder when the walls between the new and old come down.  The good news is…it’s only noisy during the day when work is being done.

To see our complete preplanning checklist for your project, check out this previous post titled Tips to Add on to Your Home.







Home Additions: Sizing Your HVAC Equipment

As an owner-builder, you want to make sure your new home additions will be of the highest quality with the fewest possible problems.  So make sure you require your HVAC subcontractor to run a manual J calculation (or equivalent) to check the equipment sizing when you add on to your home.  This calculation will check to make sure the existing furnace and air conditioner will be properly condition both the old and the new space.  The last thing you want to happen when you add on to your home is to end up with a less comfortable space.

No Rule of Thumb: Could you imagine Ford or GM sizing a car engine based on what the designer “feels” would work best?  They always do the engineering calculations for all of the items affected by the engine to make certain it performs optimally.  So, why do we let our HVAC subcontractors look at your home and use a rule of thumb method to size your furnace or air conditioner?  I can’t tell you how many heating guys I have come across that tell me, without looking at a new architectural plan, exactly what type of system is required.  When asked how they came up with the design they typically answer “from years of experience.”  Ok, great.  You’ve been around a long time and you’re good at what you do.  So prove to me that you know what you’re talking about and do a manual J calculation (or equivalent) to prove it.  For tips on finding the right HVAC contractor when you add on to your home go to our video Finding Quality Subcontractors.

What is a Manual J Calculation?: This calculation takes into consideration a number of different factors that affect the performance of the heating and cooling system for your particular home.  Below is a list of the most important factors with a description of each.

  • Window types and locations (including glass size and type):  Careful consideration should be given to locations of windows in your new design.  These can have a dramatic affect on your HVAC system.  Also important are glass type including Low-E coatings, gases between panes, and number of panes as well as the frame type (i.e. vinyl, wood, aluminum, fiberglass…etc.)

  • How tight your home is or will be.  Newer homes are being built much tighter than homes built even ten to fifteen years ago.  With foams, caulks and building science methods, we are keeping more of the cold air out.  You will most likely choose to use these new methods when you add on to your home.

  • Insulation levels:  All insulation must be considered into the design including ceiling walls, cantilevers, basement, crawl space…etc.

  • Size, spacial configuration and orientation of your home:  Having more space typically means bigger equipment will be required (with all else being equal).  The configuration of your new space can also have an impact.  An example of this would be volume ceilings…in a cold climate, high ceilings can make a room difficult to keep warm but in the hot weather, a vaulted ceiling may actually save on cooling costs.  The orientation of your home as a huge impact on the design of your system as direct sunlight can put additional loading on your system.  Roof overhangs, careful window placement, and certain building materials will help control solar heat gain and can reduce equipment size requirements.

  • Occupants (age and quantity):  Occupants give off heat themselves…the more people you have in the home, the bigger affect it will have on heating and cooling capacity.

  • Climate:  Obviously the outside temperature will play a major role in the sizing of your HVAC equipment.

The most common misconception for heating and cooling systems is the notion that bigger is better.  If your system is over-sized, it becomes inefficient and creates wider temperature swings in your home.  It may also require more maintenance and need to be replaced sooner.  So, check the calculation your subcontractor has performed on your specific home and make sure the equipment being installed corresponds with the results of the calculations.  To see an overview of preplanning activities for your project to add on to your home, go to our previous post titled Tips to Add On To Your Home.




Add on to Your Home: Check Insurance Coverage

As an owner-builder, you want to make sure you have insurance coverage for your new project both during and after construction.  This insurance should protect you in case of fire and weather damage, theft and accidental injury.  There are several different types of insurance available to protect you when you add on to your home…let’s take a look at each.

Builders Risk Insurance: Builder’s risk is a type of property insurance that provides coverage for physical damage to the structure during construction. This type of coverage typically indemnifies you against losses due to fire, vandalism, lightning, wind, and similar forces during the construction phase. It usually does not cover earthquake, flood, acts of war, or intentional acts of the owner.  The owner-builder typically buys this insurance.  If you decide to hire a general contractor however, you can write into the contract that he is responsible for obtaining the insurance.  Builder’s risk insurance is also commonly referred to as Course of Construction Insurance. 

General Liability Insurance: General liability insurance covers you from liability in the event that someone is injured when you add on to your home.  The construction site is a dangerous place that has many hazards including falling objects, trenches, fall hazards…etc.  So, check with your insurance agent to get the proper coverage in the event that an accident occurs.  One accident can quickly negate all of your hard work through high legal fees…so don’t overlook general liability coverage.  Your agent will also give you the requirements for any subcontractors that will work on your project.  I have typically required my trades to have a minimum of $1 Million in general liability coverage with me being named as an additional insured on their policy.  You will want to get copies of these policies from each subcontractor prior to starting a project to add on to your home.  You will also want to check to make sure the coverage and policy period are correct.

Workman’s Compensation Insurance: This is state regulated so the location of your project determines what type of coverage you might need.  Workman’s compensation insurance will cover lost wages, medical expenses, rehabilitation services and death from an injury or illness sustained on your project to add on to your home.  You will want to make sure your subcontractors carry at least the minimum required by the state.  Your insurance agent should be able to help you with this.

As an owner-builder, you want to be certain you aren’t taking any unnecessary risks when you add on to your home, so take the time to make sure you have proper insurance coverage.  I have seen issues come up years after an alleged accident took place on a job site and some of these involved tens of thousands of dollars.  Keep in mind, some of the types of insurance we talked about here may not be needed for your home addition as you already have insurance on your existing home through your homeowner’s insurance policy.  Be sure to check with your homeowner’s insurance agent to see what will be covered and what types of coverage you will need to add.  






Over at the Armchair Builder Blog we regularly share tips for saving money and preventing hassles.  We cover...

  • Basement Finishing
  • Kitchen & Bath Remodel
  • Tips for Hiring Subcontractors
  • Resources to Build Your Own Home 
  • Home Repair Techniques
  • DIY (because sometimes it just make sense to do it yourself)

Check out our latest insider building tips at the AB Blog!


The Latest from the Armchair Builder Blog...
April 9th
What is a Construction Loan? Building your dream home can be incredibly rewarding. But when you choose the owner-builder path, taking on the role of general contractor, it throws another layer of complexity onto an already intricate process. Securing a co…

Follow us on: Facebook Twitter YouTube