Building Out The Basement
 

I would like to build out my basement. We have 1,000 sq ft of basement w/ appx 8 foot headroom from joists to slab. It is dry all year. Some small high windows set in the basement walls. I think I can fit a guest/in-law suite down there, with a kitchenette and bathroom. The goal is to have the basement look just like the rest of the house - similar hardwood floors, molding and details - rather than like an afterthought add-on. Finished headroom could be about 7 feet 8-9 inches.

My thought would be to build out appx half of it, 500-700 sq ft. Cut larger windows in the walls, set in wells, for egress and light. Will need to cut the slab to tie into the main drain, clear on the other side of the basement. And run water supply, electrical, HVAC ducting. Think can do this w/o moving the furnace. I would have contractors do the preceding, then frame, soundproof, insulate, drywall, floor, and finish myself. With permits of course.

I am very early in my thinking here. Any suggestions, cautionary tales, lessons learned, from guys who have done this sort of thing?

Do you have a walk out or just egress windows? What is the exterior cladding? Any sump pump issues? Structurally what's above, a one story rambler or something bigger? Off the top of my head it sounds like you're on the right track. Hiring sheetrockers isn't too expensive and might really be worth it, at least hiring the mud work done.

Just egress windows, not a daylight basement. Cladding is wood siding, but it starts above the basement windows. No sump pump. The grade at the house is 6 feet above street level, and downspouts are all tied into drains, no stains etc to suggest basement has ever had water issues and has stayed dry for us through two wet winters (is there any other kind in Portland).

House is 3 story (two main floors plus 700 sq ft finished attic) above the basement, 100 yrs old, sort of craftsman-ish - locally we call it a "four-square", anyway is a traditional looking house. Including all 1000 sq ft of basement, house would be 4010 sq ft, but I won't build out entire basement, want to leave some room for workshop/darkroom. Also there is part of the basement that has a lot of overhead HVAC ducting, would be too complicated to build around and headroom compromised there, so that's where the workshop will go.

Yes, I am terrible at mudding, but main house walls are not smooth, are a sort of textured look so I would hire someone to do that. I want to take the oppty to add a supporting post in one spot, figure could have that part of the slab cut and a deeper footing poured, while they are in there trenching for the drain.

Around here stuff sells for $250/sqft. I figure even if well-finished basement only gets $150/sqft, I should be able to add value net of costs. Costs appx $40-50K to get 500+ sq ft of basement built out here (some friends have done it), I am hoping to do it for $15-20K to trades plus sweat. I might have to get a bigger electrical panel though.

Need to research soundproofing, want the guest/inlaw quarters to not hear every footstep from above.

Big lesson I learned is to make sure the capacity for the HVAC equipment is up the task of handling the additional sq/ft. I am looking to upgrade after this winter....oops.

Look up a product called Radon Seal before you start. Do all the concrete. Farm out the window enlargement for an agreed on price, or don't cut the concrete. If you can use your bulkhead for egress, do it.

One concern: without a separate exit, I'm not sure if code will allow sleep space in a basement.

If they do, I would not recommend wood floors if there is not a gravity drain, non-sump pump method of drainage.

We have a finished basement, with an in-law apartment, and are moving to this:

http://www.increte.com/

In our case, the shower and toilet required a separate sump pump system below the slab to tie into the sewer drain. Not really an issue.

Concerning the kitchenette, check with the fire code folks and your insurance company about specific appliances they will allow.

Plus you dont need to nail it down like a real hardwood floor. Im not sure how it would fare on a cold slab though. definatly need to research that.

As far as the hvac i highly doubt youll need a bigger unit being that its in the basement where its less effected by the outside temp. And 90% of the time contractors will claim you need a bigger unit when you dont. I work with them so i know :rolleyes:

Think about some radiant floor heating. You won't need to add anything other then a hot water source. I installed one recently into a garage and it is very nice. You will always be battling the cold concrete slab in a basement. For the summer you will need AC, but basements usually stay cool and you won't need much to keep it comfortable. Just a thought.

Is that stuff DYI. Looin gto do something similar to the pattern concrete at the new place.

Good idea about the radiant floor heating. Might be nice to have the guest/inlaw suite on a separate heating system, since aged relatives etc often like it warmer than I'd like. Don't want to give up too much headroom, though.

Not hung up on real hardwood vs engineered vs laminate, as long as it matches the main house decently well.

Anyone know about sound insulating a ceiling, to reduce footstep noise from overhead?

John, I'm finishing my basement right now, and have looked into soundproofing a lot. Nothing is more annoying than hearing every footstep on the floor above, and if you have wood floors it's especially bad. There's a number of different ways you can soundproof a ceiling. There's sound insulation, which is similar to fiberglass insulation, that you place above the sheetrock. There's various forms of foam insulation. Some people double the sheetrock, which of course further reduces your ceiling height. There's also a product called Quiet Rock (http://www.quietsolution.com/html/quietrock.html), which makes a form of pre-insulated sheetrock. It doesn't appear to be cheap, I'm yet to compare it to regular sheetrock + sound insulation. If price isn't too high, it's probably the approach I'll take, as it's quick and easy.

You should be fine. A wood siding, egress windows, cement floor, probably a rectangular box with prefect right angles. Nothing too complex. Have a professional look at your walls to make sure there aren't any structural issues. Have a carpenter deal with the egress windows. Look into tile or linoleum for the flooring. Tile is very nice for basements if you can do it yourself. Sheet vinyl (linoleum) has come a long way and is much cheaper and easier to install. Do what you feel comfortable doing and sub out the rest. I think you'll be able to handle it and will be happy with the results.