How much to build a garage with and apartment on top?

Answer 1

Good question! These answers will depend on your location. These answers are regarding southern Alberta-Canada.

1. Garage builders: 22'x24' standard garage with electrical and gas line $24,000. Adding a "mother-in-law" suite on top it jumps to $140,000 (which would include Plumbing). Why? Must dig down further to add extra foundation to support weight, rough in the water and sewage lines, installing kitchen and bathroom.

2. Same above size but only rough in the upstairs electrical, gas, and plumbing. (you would build your own kitchen and bathroom and tie in all roughed in utilities. Somewhere around $115,000 with a garage builder. In short you are building a cold room above with your utilities roughed in for future plans.

3. You become the general contractor and hire tradesmen to pour in the concrete, frame the building, tie in electrical and gas and plumbing, you don't lift a finger. A lot less than $115,000 depending on which tradesmen you hire. Tradesmen from a huge company of 100 tradesmen will be more expensive than say a tradesmen with his own company of 4 employees who's been a contractor for 30 years. Competition, competition, competition!

My experience and education? Amateur. However I have been researching, in Alberta, building a detached 22'x28' garage (No above suite). 2' Apron, 2 standard windows, space saving trusses (think overhead storage), 2x6 frame, 8'x16' door, 36" man door, vinyl siding, asphalt shingles.

6 local quotes from reputable garage builders average $32,000.

Adding together quotes for hiring tradesmen: $19,000 (Concrete, frame, electrical+gas, siding, insulation, and roof)

How I'm saving even more money? I have enough experience to complete concrete pad myself with help. Will put up my siding, shingles, and insulation myself. Haven't calculated how much I'm saving but this will be far less than $19,000. I'm estimating around $14,000.

Plan:

DIY

a. Apply for a standard building permit.

b. Purchasing a garage kit with siding

c. Concrete slab (4" concrete, 6" curb wall, gravel underneath, and 12" excavation in total for prep and level off

d. Trenching for the electrical and gas lines

e. Siding (plywood, tyvek, and vinyl siding)

f. Roof (plywood, tar paper, shingles, eavesthrough, fasia etc.)

g. Purchase overhead gas furnace/heater ($500; garage builders charging $1,000+ installation)

Tradesmen

a. Building frame

b. Running electrical and gas lines (through trench I dug) and install 100 amp service, and having my pre-purchased heater installed. (electrical and natural gas permits are purchased by the tradesmen and charged to you in their bill)

c. Garage door. I could do this myself but I want a perfect fit and seal and would rather have a pro install it.

Your other option is to purchase a "garage kit" at your local home improvement store (Here we have Rona, Home Depot, and Totem). However a carpenter who will put your frame up might be able to get his lumber far cheaper than you could in a kit because he buys in bulk. In my case by using the carpenter I have chosen is about the same cost.

These are all things to think about. I'm in no way an expert or a tradesmen. I'm simply sharing with you my results of my research in building my garage. Oh and I was looking into a mother in law suite above as well however my neighborhood zoning laws are preventing me from building anything higher than 15' with a development permit. Having a cold room above (with a development permit) would also be declined.

Last note: If you live in a metropolitan center check your local zoning laws through your city or municipality. You might not be allowed to build a suite above. You might be limited to only 22'x24' for example.

Answer 2

quite much depending on your circumstance, you will clearly have to elaborate greatly! Thanks!