Michael - just a word of caution. We've moved away from using the $/sq. ft estimating technique. It just would never get us close enough. I think the reason is that your repairs tend to come from multiple categories: very cosmetic(carpet) to fairly substantial (new kitchen cabinets and appliances) to major systems (HVAC, roof, electrical) but rarely falls squarely into just one of those three categories. It can get you a very rough estimate, in our opinion, but we find breaking down your estimate into major line items will get you much closer. Here's a list of the major line items we tend to calculate on every flip:
- roof (removal or re-roof? Dry rot repair AND roof replacement? Sub-roof damage repair?)
-HVAC, furnace, evap cooler
- windows
-flooring (by type, sq. footage and quality)
- trim for windows and floors, interior & exterior trim (figure linear ft. This really adds up!)
- sub-flooring repairs
- kitchen & bathroom remodel (just a new vanity or total re-do?)
- moving walls?
- electrical?
- appliances (range, dishwasher, garbage disposal, vent hood, water heater. Note: we don't budget for refrigerators in flips. Buyer has to provide that.)
- Exterior & interior paint (pretty much every house needs this)
- garage doors & garage door openers?
- plumbing?
- landscaping?
- Interior & exterior doors
- Inspections
- Permits
- cleaning (there's a lot of dust and mess after a remodel)
This isn't every cost, but we do find these are the biggies. After you've looked at enough houses and priced enough material (seems like we lived at Home Depot for a couple of weeks) you can run these numbers pretty quickly. We still do refer to J Scott's book for estimating, also, but have come to rely on our own numbers. Our numbers are local and current, and sometimes that makes a huge difference.
Also - just an FYI. After buying a ton of stuff recently at Home Depot, I was talking to a manager at Lowe's. He was a little offended when I told him how much we had bought at Home Depot. His first response was "we'll match their prices." I said "yeah, but only if it's the exact same item, right?" He agreed that was true. But then he went one better. He said, 'look, we really want your business. Gather a list of the products you want, email it to me, and I'll run it through our pro discount program. It will save 5% - 20% off each item." I still had a lot to buy so I went home, scrolled through their website, picked out about $2500 worth of stuff and emailed it to him. Sure enough, he came back with a line item price on every item showing the amount each was discounted. The total discount on the order was about 15%, which in my book is substantial, especially since we're not a huge buyer yet. Better yet, he has consistently applied that same 15% to every product I've bought since. I'm not here to plug Lowe's. I don't prefer their product over anyone else's - big box store products are all pretty much the same - but I'm telling you this so you know to ask for it. Ask for it anywhere. DON'T act like a typical retail consumer when you go to purchase your products. Let them know you're in the business. It makes a ton of difference.
Good luck!