Friday, September 26, 2008

Total DIY loft conversion costing so far

I've posted a link to this blog on a forum . a few people interested in the costing so:

Fairly accurate costing for DIY 16m2 loft conversion room with 4m2 landing area

Not counting the complete new roof in slate with breathable membrane done by a contractor, cost including supply and fitting of steels and installation of velux £6000 plus vat. I’ve included the material cost of steels and velux.

4 velux, 3 off 1140 x 1180, 1 being escape spec, 1 off 780 x 980 - £1188
Rockwool Flexi to bring fire resistance of lathe and plaster ceilings up to spec - £322
Chicken wire to support above - £80
Celcon blocks, sand cement for fire wall to neighbours -£191
Steels UB’s 230x90x32kg/m PFC 1off 4900mm 1 off 4000mm - £150 est.
Joist hangers - £47
Timber for structural and stud walls - £265
Radiator and various hardware - £298
Chipboard flooring P5 grade plus some PSE - £157
Kingspan for roof and ashlar - £348
Kingspan drylining K17 for brick walls - £305
More assorted hardware - £162
Electric, cable and high spec fittings - £180 est
Timber for stairs - £450 est
Plaster board - £129
Skirting and architrave - £99
Skim Plaster, bead and plasterer for 2 days - £165
Assorted other bits and bobs - £120 est
1/2hr fire door and frame - £122
Flooring Oak veneered laminate, underlay, edging -£332
Estimate of others, eg. smoke alarms, paint, lost receipts - £300

Structural engineers calcs - £264
Building control submission - £130
Building control inspection - £283
Electric certification - £80
(all work under supervision of electrician (father in-law)

If I’ve missed anything obvious let me know.

Total cost - £6167


  1. This is useful

  2. Glad you've found the info useful. It's the kind of detail that's often find hard to find on the internet. It's good to share what knowledge I gain from doing the things.


  3. wow, you certainly are talented. The information on your blog and site is great thank you for taking the time to explain it to us simpletons.

  4. Becky, Thanks for leaving a comment. It's good to know the info is useful. And as for praising my talent, well I'm blushing now.

  5. I'm not doing a loft conversion or even thinking about doing one but the whole blog is incredible, I have followed it all the way through, your a genius

  6. Skim Plaster, bead and plasterer for 2 days - £165

    is that all materials and plasterer for the whole conversion?
    how much is the plasterer working per day?
    is this typical amount?
    Thank you.

  7. Anon, It might not be typical but if you ask around there are guys out there who would normally be subbing for other builders. Inbetween bigger jobs they pick up what they can. £60 a day (but it wasn't full days maybe 5 or 6 hrs). All he had to do was tape the joints and skim. That leaves £45 for the materials, Finish plaster per bag being around about a £5 + Beading and tape.


  8. I have to say I am mightily impressed Andy. Nice work on your loft conversion with some real hard graft put in there.
    Chris TLC, Kent

  9. Loft conversions are a great addition to the home setup. They are usually nice and bright because they are situated on the top floor and have the benefit of skylight windows that give plenty of natural sunlight.