Planning a Home Addition Like a Boss

If you want to plan your first home addition, this article is an excellent place to start. I’m going to teach you some things that you probably haven’t thought about. We will talk about:

  1. Prioritizing the important items
  2. Hidden costs and how to get around some
  3. Sizing your addition
  4. When you should hire an architect versus a builder
  5. Some common ways people go off the rails with their original budget

When you are through with this article, you should be in a much better position to speak to a contractor or architect about your project.

Everything’s a Problem to Be Solved

You have a problem. For argument’s sake, let’s assume an addition to your home will solve your problem(s). To plan a proper solution we need to define exactly what the specific problems are. Typically, deficiency problems with one’s home fall into 6 categories (with some overlap between them):

  1. Living space (common areas, living rooms, dining rooms)
  2. Sleeping space (bedrooms, guest rooms)
  3. Comfort & Convenience (bathrooms, laundry rooms, storage)
  4. Cooking
  5. Function & Flow
  6. Business (Office space, rental income, resale value)

Your first order of business is to define your problems and write them out. Most home problems can be solved. When you clearly define them, you can get more focused on achieving your goals.

Here are some example problems you might jot down:

  1. Kitchen storage space is inadequate
  2. Can’t see my children playing in the yard when I’m cooking
  3. The distance between the dining area and kitchen feels too far and disconnected from family and guests
  4. The kitchen floor is cold in the winter and the natural light is terrible
  5. We hate having to go down to the basement to do our laundry
  6. We need a guest room on the first floor with easy access to a bathroom so elderly parents are comfortable

Needs Versus Wants

You should develop a list of needs and a list of wants. Unless money is no object for you, if you’re like most of us, it’s good to wish, but it’s important to be in reality.

This step will help guide your decision-making so that you don’t go over budget on things you don’t really “need.”

Sitting down with your partner and writing out wants and needs lists.

Example list of “needs for an office addition W/ bathroom and laundry area:

  1. Needs to have separate outside entrance as well as access from inside of the house
  2. Needs to have concealed space for stackable washer/ dryer
  3. Needs to have hardwood floors
  4. Needs to have ample natural light
  5. Needs to have a separate heating zone
  6. Needs to have ample noise insulation from adjacent rooms
  7. Needs to function as a guest bedroom as a secondary use
  8. Needs to allow for easy laundry room access from inside the house

Example list of “wants” for an office addition W/ bathroom and laundry area:

  1. Want skylight for added light
  2. Want oak wood flooring
  3. Want recessed lighting
  4. Want porcelain tile in the bathroom
  5. Want 12-foot ceilings
  6. Want a separate shower and tub
  7. Want claw foot cast iron tub
  8. Want recessed cutouts in sheetrock for plants and decorative items
  9. Want triple-pane glass windows
  10. Want an externally mounted A/C unit (not window mounted)

You can see how important it is to identify your wants versus your needs because once you start putting numbers on these items, it becomes a different ball game. Doing this kind of soul-searching beforehand makes the decision process much easier.

How Big Should My Addition Be?

Contractor looking at drawing superimposed on pert of image.

Once you are clear on the problems needing to be solved and what your wants versus your needs are, an architect can help you get clear on the amount of space you need to solve your problems within your budget.

Though you may be clear on whether you want to build out or build up (adding a story), an architect may also be able to add perspective that you may not have considered. This planning phase can be worth every penny when you are working with someone skilled.

Hidden costs to consider when planning an addition:

Permit Costs:
The cost of your permit is based on the square footage of your addition. This fee is relatively small compared to the overall cost of the renovation.

Septic Tank Size:
Adding more “bedrooms” means your septic tank will have to be rated to handle the extra capacity. Yes, the size of your septic tank is no just dictated by the number of bathrooms and fixtures, but also the number of bedrooms. For example, a 2 bedroom house assumes 4 occupants, and a 3 bedroom home, assumes 6 occupants.

Property Taxes:
More bedrooms could raise your property taxes. The taxman will want a piece. Sad but true.

Pro Tip:
More “bedrooms,” may not be an option for you based on the size of your septic tank and leach field. However, there may be a way around that. Perhaps you could designate a room as true office space and set it up with a sleeper sofa or Murphy bed. Once the project is completed, there is no one that can tell you (ahem) that you can’t use a room in your home as a guest bedroom if you wanted to.

Do I Contact a Builder or an Architect First?

Even if you are building your addition yourself, you will need a blueprint for the work to be done. Not only will you need this as a construction guide, but you will also need this to obtain a permit from your local building department. You can’t just shoot from the hip and build it, at least not if you’re going to follow zoning and permit regulations.

If you plan to do the construction yourself, then you need to get in touch with an architect to have some plans drawn up. Once the plans are drawn, you’ll need an engineer’s stamp of approval. Most architects work closely with engineers who will approve their drawings so you’ll get both the plans and the engineer’s stamp in one bundle.

If you are not a DIY (do it yourself) type, then you need to decide if you will engage an architect or a builder first.

And that is an interesting dilemma … 

An architect will almost always tell you it’s better to contact an architect first, but a builder will tell you the complete opposite. Imagine that?

The thing is, once the plans are drawn up, the architect is usually out of the equation unless something comes up that needs to be clarified or changed. So the amount of time you actually spend with your architect when building an addition pales in comparison to the amount of time you could potentially spend with your builder, who will be on-site with you daily and potentially down the road after completion.

With this in mind, when planning an addition for your home, one could argue that it would be a better idea to source your builder first. Once you have a builder you want to work with, ask that builder to recommend an architect. This way you will have the builder you want and an architect that the builder has a working relationship.

Anthony Ferrara of North East Remodeling Group going over plans with a client.

You better make sure that you have a good rapport with your contractor because you will be spending a lot of time together.

What’s in a Blueprint and Why You Need One?

You need blueprint drawings so that a builder can bid on the job and you know how much it’s all going to cost. This all starts with the drawings. The drawings will dictate the materials to be used and the structural specifications necessary for executing the job within building code and setback variances. Without plans, nothing gets done and no one really knows how much any of it will cost.

How a Blueprint Determines Job Cost

Here’s how it goes. An architect draws up plans with the stated desires of the client. The contractor puts prices on the job based on average costs stated on plans. For example, the plans might specify 500 square feet of ceramic tile, at an average cost of 50 cents per square foot. That’s why it’s really important to know the products you want to be installed before plans are drawn up. (More on that in a minute.)

What Will a Blueprint Actually Cost Me?

Prices will vary based on the area you live in and the demand for your architect’s services. The national average to have blueprints drafted for a 1,000 square foot addition is around $1,200-$1,500. There will be other fees that can also raise costs, such as interior/ exterior schematic designs and permit application fees. When all is said and done, you may expect to pay your architect around $3,000-$5,000 or more for your addition blueprints.

What Kind of Homeowner Are You?

The DIY homeowner:
If you plan on being very involved in the construction process because you’ve got skills and have friends in the business that might be able to help you with different phases, then maybe it makes sense for you to be the “GC” (general contractor) for the project.

You’ll have the joy of being the one in charge of hiring and coordinating various subcontractors to complete each phase of the job. This will save you a lot of money but will require that you take on a lot more responsibility and potential aggravation. The upshot is that for some aspects of the job, you may be the one ordering materials and this could save you some bucks because you will not be paying a builder’s markup on materials.

Pro-tip for DIYs:
If you have a local building or plumbing supply company that you are planning on doing a lot of business with over a particular span of time, it may be worthwhile to have a conversation with them. You could explain your situation and your desire to give them the bulk of your business in exchange for contractor pricing. If you truly are the handy type that does occasional side projects for friends, then it would certainly behoove you to have that conversation and get yourself set up with a contractor’s account.

The Anti-DIY homeowner:
If you are not the handy type and you are not interested in managing your home addition, then you will be paying a premium, but that might be just fine for you. Many homeowners do fall into this category. This means you need to find yourself a builder you feel comfortable working with.

How to Stay on Budget and Reduce Costs

Typically homeowners are not prepared for costs. You paid for your plans, but once you’ve settled on your design, each revision thereafter can cost you. The best way to stay on track with your budget is to get clear on the materials you will be using before finalizing the plans.

Image of product samples and plans.

Research products:
The most important thing is for the client to research the products they want to use. Usually, it’s the materials on the finish-end that will cause project costs to balloon. So spend the necessary time to get clear on what kind of lighting, flooring, paint, windows, cabinets, fixture, etc you want going in. Don’t make these decisions while you’re in the middle of the project.

Source your fixtures:
You can potentially save a bundle by searching online, using sites like Craig’s List. Sometimes you can also find that local stores have “seconds.” These are products that have been slightly damaged and are less than perfect.

One of my clients recently picked up a beautiful $900 cast iron tub for $300 because it had a small scratch on the outside corner. Being resourceful in this department can make a huge difference.

Avoid this classic mistake:
Let’s go back to an earlier example. Your plans indicated 500 square feet of ceramic tile, at an average cost of 50 cents per square foot. But you and your spouse go to Home Depot and decide you like the $1.50 per square foot porcelain tile. That’s exactly how budgets go off track.

If the client does their homework and knows exactly what they want when they sit down with the architect drawing up the plans, then they can get a quote from the contractor that’s pretty close to exactly what it’s going to cost to complete the project.

Learn From Your Friends

Friends sharing wisdom about planning a home addition.

I can’t emphasize enough how important it is to talk to friends and tap into their experiences, regrets and realizations. People love to talk about their renovations. Ask experienced friends what they would have done differently if they could do their addition again? Dig deep, you might be surprised at what you learn.

True Story:
Recently, I was speaking to a non-contractor friend of mine in another state who redid his bathroom. He wanted radiant floor heat, but he said tying into his existing hot water heating system with radiant floor heat would have significantly increased the cost of the project, so he opted for baseboard heat.

When I told him about the small 8×8’ electric radiant heating system kit with a timer thermostat that we had just installed in a bathroom for a client, he was surprised to find out how little it would have cost him.

The point is, talk to people! Learn from the mistakes and wisdom of others. Think about how valuable life experience is. Once your addition is completed, you yourself will be an expert compared to someone that’s never been through it.

Consider The Exterior

Eventually, you will need to consider the exterior because you will need to tie in the new exterior siding to the old exterior. So at some point, this needs to be considered. Will you be residing the entire house or will you try to match new siding material to old siding material?

Will you even be able to match the old siding or paint color to the existing siding? Maybe it makes good sense to reside or paint the whole house because it’s just time to do it? Either way, the exterior work will need to be considered in the equation.

If you can time your project so that the exterior phase is done before the snow flies, that would be helpful. If not, you may have to wrap the exterior of your addition in Tyvek® for the winter and complete the project when the weather breaks.

Wall rebuilt and wrapped

You can ride out the winter with your addition wrapped in Tyvek until the weather breaks.

Consider the Style of The House

Think about the style of the house. For instance, if your home is using old-school radiators for heat, will you be continuing with that?  Or will you be upgrading to radiant floor heat? Is it more important to maintain consistency and charm over comfort and efficiency?

The Building Inspector: Friend or Foe?

Building inspector checking over an addition.

Depending on your perspective, a building inspector can be a friend or foe. But for the homeowner, hiring a contractor, the building inspector is most definitely your friend. Even if the word on the street is that your inspector is a ball-buster, it works in your favor. Or at least that’s how you should be thinking about it.

The local building inspector checks the contractor’s work to make sure that the work being done is in alignment with building standards and code. A building inspector that does his job, can catch poor workmanship and save you from potential liability and problems down the road. So look forward to those inspections. They’re for your benefit.

Hiring a Contractor

When you hire one company to do everything, there can be advantages. However, in most cases, architects are not also doing the building and construction companies are not drawing up blueprints.

That said, when communication channels are open between builder, architect and engineer, things can happen fast and potentially eliminate setbacks. If there are changes that need to happen on the fly, then plans can be amended quickly without delays because all parties have a working relationship. The importance of this working relationship between architect, engineer, and contractor can’t be overstated.

Of course, we are biased about our assertion that you should find a contractor that you want to work with and let the contractor recommend the architect because in the end you will be spending more time with the contractor, and he’s the one that will have your back should you have problems down the road.


  1. where does one start when the basement wall must be addressed before any renovations can begin? an engineer? a contractor? an architecture?

    • Hi Jan, I never heard back from you. Without knowing more about your specific situation, it’s difficult to make a recommendation but I can say this. If you are having structural problems concerning the foundation, you absolutely cannot go wrong by consulting a local engineer. Once you have drawings stamped by an engineer, you can take those plans to a contractor to execute them. No need for an architect at this juncture unless you have major structural design aspirations? Any plans drawn up by an architect will need to be stamped by an engineer. Again, the engineer’s stamp is still the last word. Hope that’s helpful to you.

  2. when we moved into our home 20 years ago. We noticed that the previous owners removed peg boards in the move to reveal cracks along the blocks in the wall. My husband immediately placed support beams every foot? approximately. Now, we are planning an addition that does include this wall as support. And we know that even if we were not going to do the addition, IF we ever were to sell, it will be a point of question.

    • Jan, Since this basement wall will also impact your new addition, and you are likely planning on hiring an architect to draw up plans, it may make sense in this instance to speak to your architect first. The architect will need to have his engineer approve any structural remediation that needs to take place. You may end up paying a slight markup for an engineer’s services if you do it this way, but there is an inherent benefit to having the input of an engineer that has a working relationship and an open line of communication with your architect. As you pointed out, now is the time to address any structural issues so that they don’t cause problems with your addition and/ or get flagged on a home inspection if or when you ever decide to sell. Is that helpful?

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