DIY house extension... Should I?

[Pinter75]

Howdy.

Now I ain't a builder, but I know how to use a hammer.

Recently I got planning permission for a small extension. Saved a few quid by drawing the plans and being my own agent.

Now I have built a brick extension before, but a very small one. Still it is standing, does not leak and is well insulated. It was technically a lean-to shed, so single skin walls.

Also last year I built my own conservatoryhttp://conservatoryproject.blogspot.co.uk/ So I am not afraid of jumping in and using common sense, and Google to find out how to do stuff.

We have been getting in quotes for the work at about 15K. My brain is thinking it is about 3k in materials and the rest is labour. So I am toying with the idea of doing it myself. All Building reg plans are done, so I know what to do.

We are on the south coast, so it won't have a solid concrete floor, as we are on a slope. Also we hit hard chalk about 8" down.

Anyone on here built their own extension?

 

[lude1962]

I suspect local building control may want to inspect it and get their share of the money

 

[Pinter75]

I suspect local building control may want to inspect it and get their share of the money

They already have their money. Building notice is in.

 

[Tesla]

We have been fully renovating our house for the past year, to the extent we couldn't live in it for 9 months.

Just about to self build a small extension to replace an existing single skin "lean-to".

I have groundworkers on site at present to replace a couple of drains and pour the foundation. I then have a brick layer laying 4 courses of blocks to bring me up to DPC.

Then I am doing the rest, timber frame which I know I can make a nice job of.

 

[dal]

If you can do it yourself I'd go for it especially if you can save yourself 12k.

 

[john_s]

I'd definitely go for it.

 

[boxman2000]

If you have the time then yes I'd definitely do it yourself. Just the savings alone would convince me, let alone the satisfaction of building it yourself.

 

[Nedved11]

Definitely give it a shot. I got a double storey extension and single storey extension to the kitchen to build in the not too distant future. What did you use to draw the plans with. My planning department is very fussy. The single story will be within permitted development though.

 

[Abyss]

Sounds like you are up for the challenge, so if you are willing to live next to a building site for a longer period of time I'd say go for it.

I would however take a look at your numbers. £3k in materials is very light. The cost of the groundworks, foundations and brick walls will likely eat up most of this, and that's before you put on a roof, fit windows/doors, plasterboard, electrics, heating, floor finishes, decorate etc.

You may also want to factor in the cost of an electrician and plumber depending on your competency; you'll certainly need someone with part P to do some of the works.

For an average sized extension built myself including finishes I'd be working on at least £6k-£8k. This includes materials, minimal labour for the bits I couldn't do and any plant/skip hire.

 

[D.P.]

3K materials sounds way off.

You then have to factor what your free time is worth. Also, if finances are a bg driving factor then i would check other options such as working over time, second job or contracting. Depending on your skills you may find it cheaper simply to work more and pay someone else to do the manual work.

people never seem to realize that when buying a "fixer upper". They spend all evening and weekend for a year doing a place up when they could have earned far more money then what was saved doing contracting not the side, let alone the cost of having no personal time.

 

[Pinter75]

We will have a floating floor, as the house is on a hill. Foundations are for the 2 walls only. 2 windows and it is only 3x2.5m with a flat roof.

Materials are just some cement, blocks, 2 windows, timber and a few other bits and bobs.

Seeing that our conservatory was quoted at £20, I did it myself for £6k and it was 4x3

The hardest park will be the stepped footings, but we are on hard chalk here. All depends what BR want.

As for the plans I did them in CorelDraw - bit like illustrator - but I know it better.

 

[Jez]

I don't think your material estimate is too far off for a small extension like that. I recently half self built an extension (builders for basic shell and then myself for everything else) and spent around £15k on materials, but mine was a 500sq ft footprint and built from very expensive local stone for conservation area planning reasons which ate up thousands. I also bought high spec Windows and high spec insulation etc within that price and had the footings very large to accommodate the weight of all the stone which is far more dense than brick let alone block. Oh and i also changed a lot of drainage so this included all sorts of sewer diversion pipework and new manhole materials.

I'd say go for it, but know when it's too much. My plan slowly evolved from contractors to do groundwork a only, through to them eventually building the entire shell once the magnitude of the job unfolded.

 

[Makhaira]

If you're up for doing it, then I'd get a professional in to do the groundwork and do the rest yourself.

"Why?" you ask...

Of all the things that you can't easily fix down the line, anything relating to foundations/subsidence/drainage tops the list. If you get in a pro and get that inspected, any headaches further down the line are far more likely to fall within your skillset.

Also make sure you've got an able-bodied mate on standby, some things like timber frames are a lot easier with two pairs of hands!

Best of luck .

 

[koolpc]

My brother built his own extension. Submitted his own plans too. All was spot on adn obviously to building regs.

 

[a1ex2001]

3K materials sounds way off.

You then have to factor what your free time is worth. Also, if finances are a bg driving factor then i would check other options such as working over time, second job or contracting. Depending on your skills you may find it cheaper simply to work more and pay someone else to do the manual work.

people never seem to realize that when buying a "fixer upper". They spend all evening and weekend for a year doing a place up when they could have earned far more money then what was saved doing contracting not the side, let alone the cost of having no personal time.

You negate the fact that doing up your own home is actually a rewarding experience we moved into our house a month after we bought it and had two habitable rooms over the next year or so we did up the rest and really enjoyed it. I don't want to repeat the experience but it I wouldn't change it!

 

[Pinter75]

I have lots of time. I have a strange job where I license stuff and live off the royalties. No I am not an actor or singer

I am even up for the ground works, as I don't have to excavate for a floor, just for the walls.

Umming and ahhing, as we have a 1 year old here that takes up more time than work does.

Got a Jewson account now, no sign of my Travis Perkins one!

 

[LoadsaMoney]

Seeing that our conservatory was quoted at £20, I did it myself for £6k and it was 4x3

Should have let whoever quoted you £20 do it, would have saved yourself £5,980

 

[Pinter75]

Should have let whoever quoted you £20 do it, would have saved yourself £5,980

Heh heh, you are right.

My "k" key must have stopped working with that post.

 

[DB_SamX]

Have you got Building Insurance? Just check if they are going to have any requirements e.g. a contractor might have offered a warranty on the build which would satisfy your insurers. Building Control is likely to request engineering calcs too if they haven't already been prepared and submitted.

 

[Pinter75]

Have you got Building Insurance? Just check if they are going to have any requirements e.g. a contractor might have offered a warranty on the build which would satisfy your insurers. Building Control is likely to request engineering calcs too if they haven't already been prepared and submitted.

Good point, I have not even thought about that yet. Will do some investigation. Cheers!