Garage conversion

chichee

Hello,

I am gathering quotes for a single garage conversion, and so far, I have received this quote.

Does it seem like a good price? I am based in Broxbourne, Hertfordshire.

1. Start Up
a. Prepare all detailed calculations, scale drawings of the proposed construction and layout as required by the Building Regulation Control Inspector
b. Register proposed conversion with local Building Regulation Control
c. Dig Pilot holes adjacent to garage door threshold exposing garage threshold depth
d. Meet, liaise and manage Building Regulation Control Inspector through to completion of the project

2. Strip Out
a. Remove and dispose of existing garage door and frame, cart to front and load
b. Remove and dispose of existing timber flooring, cart to front and load
c. Remove and dispose of existing dividing wall, cart to front and load
d. Temporarily remove ceiling light and provide temporary lighing
e. Remove and dispose of existing ceiling boarding, cart to front and load
f. Remove existing combi boiler, divert water and gas piping and re-site on rear external wall, extending flue through to either front garden or through flat roof

3. Threshold
a. Dig out maximum of 1.2m foundation along garage door threshold, cart to front and load
b. Shutter and pour concrete into threshold trench
c. Supply and construct a cavity wall on the footings using similar face brickwork as existing property, incorporating a dpc lapped to the dpm. Masonry to be cut in to existing brickwork to provide continuous brick line.
d. Supply and install full height insulation to the new wall with 100mm Dritherm 32 or equivalent
e. Supply and install uPVC fire access, trickle vent window and sill similar to the design of the other windows of the property

4. Floor
a. Supply and install 1200 gram dpm across whole garage floor
b. Supply and install 150mm Celotex insulation or equivalent across whole garage floor
c. Supply and install 2mm vapour barrier, with taped joints, across whole garage floor
d. Supply and install water based underfloor heating system
e. Raise floor to main property level by supplying and laying screed on top of the insulation

5. Roof
a. Remove existing flat roof felt, cart to front and load
b. Supply and lay a three layer hot torched flat roof, i.e. two layers of felt under one layer of green mineral cap sheet
c. Supply and fit new flashing
d. Supply materials and point new flashing
e. Supply 15-year guarantee for flat roof

6. Roof Lantern
a. Measure out required position of roof lantern, Cut through external roof and create a hole the measurement of lantern
b. Supply and fit additional ceiling joists and trimmers
c. Supply and fit new 1.9Wm2K ‘U’ value (meets Part-L regulations) triple skinned, 1.8m x 1.2m static light dome with 150mm upstands and make watertight

7. Internal Doorway
a. Supply protection to the hall flooring
b. Supply and insert Acrows to prop load above door and wall to be removed
c. Cut away space to insert pad stones for new lintel
d. Supply and fit pad stones in accordance with Engineer drawings
e. Cut away space to insert lintel
f. Supply and fit lintel sitting squarely on pad stones in accordance with Engineer drawings
g. Remove door, frame, lining, door lintel and wall, cart to front and load
h. Make good wall ends

8. Internals
a. Supply and install 2x2 downlights
b. Supply and install 4 double gang sockets
c. Supply materials and relocate washing machine to rear of garage
d. Supply plumbing materials and install Customer Supplied Sink to rear of garage
e. Supply and install 12mm plasterboard to all internal walls
f. Supply materials and baton all external walls ready to receive insulated plasterboard
g. Supply and install insulated plasterboard to all external walls
a. Supply and install 100mm dense rockwall to ceiling between joists
b. Supply and install Soundshield plasterboard to ceiling
c. Supply materials and two coat plaster all walls and ceiling
d. Supply Dulux white emulsion and apply mist coat and two top coats of paint to all walls and ceiling
e. Supply and install 100mm skirting to all walls
f. Supply and apply Dulux white primer and topcoat to all woodwork
g. Provide part P certification for electrical works
h. All rubbish cleared, site left clean and tidy
i. Complete sign-off with Building Regulation Control Inspector

Total price all-inclusive £13,810.00

N.B. The total cost can be reduced by £1100.00 if you chose to have a standard radiator instead of underfloor heating

martinsurrey

looking at the spec I can see a few holes...

A flat roof with 100mm rockwool will never meet building regs.

you need to hit a U-value of 0.18, 2 lay felt with 125mm of rockwool on a timber deck is 0.25, you need 190mm to get to 0.18

I would expect something better than rockwool, something by Kingspan for example.

also the roof light spec seems off, new windows need to be U-value 1.6


Building regs L1B

Personally I wouldn't want a felt roof with a lantern in it, seems like asking for trouble.

Given the amount of work, building, boiler, electrics, its not crazy high, but get a few more quotes, and ask about thermal performance.

somethingcorporate

I think it's high and as per the above the spec isn't right on the insulation.

We are about to convert 3/4s of our 9m garage with a sloping roof and it's coming to the same price as yours but with full 5" kingspan in the roof, 3 large veluxs (each costing £500+) and a huge french door costing £1,200.

Get a few more quotes.

I also did the drawings for planning permission myself using MS Excel - it's very straight forward and would save you quite a lot.

chichee

martinsurrey wrote: »

looking at the spec I can see a few holes...

A flat roof with 100mm rockwool will never meet building regs.

you need to hit a U-value of 0.18, 2 lay felt with 125mm of rockwool on a timber deck is 0.25, you need 190mm to get to 0.18

I would expect something better than rockwool, something by Kingspan for example.

also the roof light spec seems off, new windows need to be U-value 1.6


Building regs L1B

Personally I wouldn't want a felt roof with a lantern in it, seems like asking for trouble.

Given the amount of work, building, boiler, electrics, its not crazy high, but get a few more quotes, and ask about thermal performance.

I will question regarding the felt roof with roof lantern and the insulation of the roof.

somethingcorporate wrote: »

I think it's high and as per the above the spec isn't right on the insulation.

We are about to convert 3/4s of our 9m garage with a sloping roof and it's coming to the same price as yours but with full 5" kingspan in the roof, 3 large veluxs (each costing £500+) and a huge french door costing £1,200.

Get a few more quotes.

I also did the drawings for planning permission myself using MS Excel - it's very straight forward and would save you quite a lot.

Unfortunately, I have no time nor idea how to utilise MS Excel to draw the pics. Other quotes, I have received are around a similar mark, and one quote for for close to £20k! :rotfl::cool: