home extension checklist...anything missing?

linda_brew

Hello, Im just drawing up a schedule of key componenets for a ground floor extension to help with budgeting. I was wondering if I had left anything obvious off my list?

Labour
Architect fees
Planning and Council fees
Skylights, flashing, frame
Flooring - tile and boards
Insulation - ceiling and wall
Foundations/Cement and steel reinforcing rods
Bricks- yellow stock
Waste Clearance
Floor Joists
Aerated Blocks
Roofing (i.e. batons, felt, brackets, nails, rawbolts, wall ties, membrane, felt etc)
Ceiling Joists
Building Mortar
Radiators and piping
Plaster etc
Plasterboard
Wood, architraves, skirting etc
Chipboard 18mm for flooring
RSJ/Lintels
Joist Hangers
Drainage, pipes, cover, connectors
French internal door
Electrics Second fix
Nails, screws, filler, dust sheets etc
Portaloo
Electrics First Fix
External French Doors
Wall tiles
New stack
DPC
Tool hire
Travel/Petrol
Rainwater fixtures
Air bricks and vents
Paint
Windows, cills, filler
Landscaping
Contingency


Would I need to budget for a concrete floor slab? Currently main area is an external concrete patio area. Would I need a party wall agreement?

Thanks
Linda

markdavey

Are you doing the extension yourselves?

If not, I can't help thinking that you are making life difficult for yourself budgeting in that way. You can get a rough idea of cost by taking the £1000-£1500 per sq m formula. Then get a few quotes from recommended builders.

I completed a 3mx8m extension last year with 3 Velux and vaulted ceilings and the build cost me £24.5k + VAT (so around £1000 per sq m) that was including all doors/mouldings, Cloakroom suite, associated plumbing/electrics for new kitchen & plastered finish (Bedfordshire area). Kitchen was extra.

I would stay away from the Party Wall act if at all possible, it just adds unnecessary costs and complications onto the build (I didn't bother although probably should have). However, if you read this, you'll get an idea of when/if you *may* need to use it.

linda_brew

thanks mark. we intend to use one main contractor for much of the shell, but several of the trades like electrics, plumbing, tiling and painting we will use people we have used before.

Its unlikely to start before August, but we want to prepare a comprehensive budget and divide in according to stages and trades so when we are getting the quotes we are clear abouts whats in and whats not if that makes sense.

Our extension is part new build, part refurbishment of two different areas of varying condition so £1000 per square metre benchmark might not fit so well here.

LittleJo

Hi,
Always allow for OSINTOTS (oh , 'suprise, I never thought of that)
Like contingency but more crucial.
Jo

linda_brew

LittleJo wrote: »

Hi,
Always allow for OSINTOTS (oh , 'suprise, I never thought of that)
Like contingency but more crucial.
Jo

:rotfl: story of my life!

yes those absolute essentials. would you include this in contingency or a separate provision and if so the % of spend you would assign?

I have a 10% contingency

mysk_girl

You only need either a concrete floor slab, or timber joists - not both. Structural engineers fees? Get one who is familiar with the ground conditions in the area. You will need a new soakaway if you are extending, so something for this?

If you haven't already got planning permission (do you definitely need it - google permitted development) you need to think about this soon. It takes a minimum of 8 weeks and can be up to 13 weeks.

I would start by finding an architect or architectural technician and get some ideas - and never underestimate how long things will take, good tradesmen and contractors do book up quickly.

Good luck!

linda_brew

mysk_girl wrote: »

You only need either a concrete floor slab, or timber joists - not both. Structural engineers fees? Get one who is familiar with the ground conditions in the area. You will need a new soakaway if you are extending, so something for this?

If you haven't already got planning permission (do you definitely need it - google permitted development) you need to think about this soon. It takes a minimum of 8 weeks and can be up to 13 weeks.

I would start by finding an architect or architectural technician and get some ideas - and never underestimate how long things will take, good tradesmen and contractors do book up quickly.

Good luck!

thanks for that re floor slab. its saved us several hundred!

we have see a couple of architects, one of which we will instruct. he was recommended by a friend and is a structural engineer, so he can "prove" cals for beams. I have included his structural work under architect.

if PP is required for us then you are right its 3-months plus time for building regs. its longer than the build and something I didnt take into account. Thats said we are aiming for an August start so just scrap home before Autumn.

mysk_girl

As for the Party Wall Act, if it applies to you be aware that you need to pay both your surveyors fees AND those for your neighbour. Can get expensive. Generally PWA applies if you are within 3m of your neighbours footings.

Does your architect have PI to cover both the architectural and structural work? And has he any idea of the local ground conditions as adverse conditions can cost a lot to get over in terms of foundation costs.

linda_brew

mysk_girl wrote: »

As for the Party Wall Act, if it applies to you be aware that you need to pay both your surveyors fees AND those for your neighbour. Can get expensive. Generally PWA applies if you are within 3m of your neighbours footings.

Does your architect have PI to cover both the architectural and structural work? And has he any idea of the local ground conditions as adverse conditions can cost a lot to get over in terms of foundation costs.

we want to avoid PWA where possible, thats for sure. would the 3m rule mean, in theory, every terraced house extension needs a PWA?

architect was recommended by a neighour. he has done work for them and their family. local architect with 40 years experience and easy to talk with.

bobthedambuilder

1. If you have any services or drains under the existing patio you'll need to budget for moving them.
2. Upgrade to CH boiler to deal with increased load?
3. Telephone / computer / media points in the extension.
4. How about external lighting and/or power supply?
5. How about an external tap for hosepipe etc for garden?

It's better to think now about the last 2 and incorporate them while you're doing the work rather than retrofit.

capeverde

portaloo !! why cant you let your builders p*ss up your hydrangeas like they do everywhere else.