Cost for Adding Extension?
We’re considering adding an extension to the garden level of our townhouse. The building is 18 x 36 while the lot 18 x 100. The addition would be 18 x 24. What is the range we should expect to pay? Thank you.
We’re considering adding an extension to the garden level of our townhouse. The building is 18 x 36 while the lot 18 x 100. The addition would be 18 x 24. What is the range we should expect to pay?
Thank you.
As a contractor, I would say the lower prices quoted here are probably not realistic for quality work once you add everything in, from permits to finishes. I recommend hiring an architect, getting your plans done, and bidding out the work for a true idea of total costs. Another idea is to enlist a contractor to perform pre-construction services for you: Not all architects are as cost-aware as others when it comes to designing, or they don’t want to reign in enthusiastic clients with realistic figures. A contractor on-board can cost out your project as it is designed, and help find ways to make adjustments that will save money while attaining a client’s design desires. Just an idea.
Tim
http://www.think-construction.com
By the way… you may want to consider that by the time the contractor has excavated for the foundation that Ed is talking about, you might as well dig a little deeper to get a true cellar space underneath the extension. You’ll pay more, but you won’t be sorry in terms of space. Otherwise, in my opinion, you are throwing away good effort without the full payback.
Because, chicken, access to these properties is very difficult. Contractors have to excavate for a foundation BY HAND and then carry out all of the dirt IN BUCKETS through an occupied house while not damaging the owner’s or the neighbor’s properties. Then they have to schlep all of the new material in through the house. Not to mention trying to get material deliveries made without clogging up the streets, getting a spot for a street container to put garbage, etc.
All of that usually goes on while the owner insists on living in the house during the construction and that at the end of the day, the house is spotless. All of that takes time…and time = $$.
I’ve asked it before and I’ll ask it again: Why is relatively straightforward building work so expensive in New York???
pete and edkopel are pretty close.
6 years ago I built a 10×16 addition to the back of my rowhouse. I went up 2 stories but most of the cost is for the first story – still the same foundation and roof.
I was the GC and saved a ton of money over contract prices I got based on the plans. Let me say it again: I was the GC and saved a ton of money over contract prices I got based on the plans. And I worked hard. I was also the heating contractor as well so counted only materials cost – no labor – for heat.
Cost me about 100K not including kitchen plumbing or deck. Not cheaped out but nothing gold plated either. 6 years ago and a lot smaller than you’re going.
I was the GC because I wanted to be – I took a sabbatical from work – and I got closer to exactly what I wanted than I would have gotten from any contractor so I didn’t incur Pete’s cost. I probably added 2 years to my life – it was pretty satisfying and I have golden bragging rights.
Any per sq ft calcs you find will be way off. My psf cost estimate was 30K. Get realistic estimates and have a good cushion.
Focus first on zoning/code issues, if you pass each of these tests, then spend time/effort on costs:
The City Bookstore sells a very useful Zoning Handbook that summarizes and illustrates the basic requirements for each zone on one page. You can find what zone you’re in by going to the DCP website and looking at the proper zoning map online.
1. Will you exceed the allowable lot coverage or open space requirements?
2. Will you exceed the allowable FAR (Floor Area Ratio).
3. If your property isn’t entirely w/in 100′ of the end of the block, you’ll need a 30′ rear yard. From the info you give, as long as you have less than a 10′ deep front yard, you’ll be o.k. on this.
4. Will the proposed addition create a situation on the first floor where you have habitable rooms (basically anything except a kitchenette or bathroom) that won’t get the required fresh air/natural light? You may be able to label a landlocked room as an accessory use space to get around this.
If you pass these tests, talk to architects who’ve done either additions or small new buildings, they’ll be able to give you pricing guidance, and avoid pitfalls that will increase costs. If you’re talking w/ someone who’s only done interior work, keep in mind that they’re out of their element.
Good Luck
Money’s important, but how long for such a project? Soup to nuts, done well and legally w/ all proper paperwork.
I wouldn’t ignore the $150,000 above. Maybe a hair high, but don’t forget the architects and engineers fees, permit fees, that things go wrong, “interior finishes”, etc. etc.
Single-story structures have a roof and foundation, electrical, and probably a big patio door; a lot of the costlier items that you would have in a larger addition and almost all of the trades would have to get paid enough to be interested in showing up. So it would cost more per square foot than a larger addition.
That said, I’m thinking of going with a single-story addition myself, so don’t lose heart!
First issue is to figure out whether your zoning and FAR will even allow for such an extension. Don’t rely on depth of adjacent building as guarantee that you can do the same.