Contract 1
1 - Foundation and ground floor slabs - on plot.
week 1-3 :
Off plot roads, communal services [ ie water, electricity and data ], site infrastructure,
drainage, highways and landscape plus services to plot boundary are installed by your
local groundworker.
Contract 1
1 - Foundation and ground floor slabs - on plot
This contract can be carried out by you independently, or
organised by the Zero Bills Home company.
On site groundworks
Trenches are dug ready for incoming services within the plot
boundary.
Manholes, inspection chambers and drains are installed and
connected to the mains
Incoming services including: Power, water and phones, are ordered
and paid for. A waterproof box is provided for all incoming site
services.
Local excavations to level ground, incl. 300mm void beneath the
ground floor are produced ready for the foundations and ground
floor slab.
A radon barrier barrier can be included at this stage if required.
Foundations & Ground floor slab
A proprietary foundation system such as the System First Beam &
Block Floor with mini-pile foundations by Roger Bullivant (shown
opposite) is installed by specialist ground contractors.
The Bullivant's system includes:
- mini-pile foundations - these typically use 6 times less concrete
than traditional strip footings
- high levels of insulation - achieving a U-value of 0.11W/m2K
- 75mm screed with DPM
- and an external blockwork plinth & perimeter ground beam ready
to receive the timber frame wall panels above.
Or alternatively, you can organise your own foundations and ground
floor slab construction.
Contract 2
2 - Superstructure - Pre-fabricated wall, floor & roof panels
week 3-5 :
On plot drainage, water, electricity and data is placed in ducts and capped at the top of
the ground floor slab.
Structural foundations, subslab insulation, and smooth ground floor screed are installed
by an approved groundworker company (such as Roger Bullivant’s or equivalent).
Contract 2
2 - Superstructure - Pre-fabricated wall, floor & roof panels
In this works package, the Zero Bills Home companies partner timber frame supplier
will supply and erect the weatherproof, insulated and airtight prefabricated timber frame structure.
The main frame of the building is made up of prefabricated timber wall and floor panels. As these are produced in factory conditions, quality
control is very high, enabling excellent airtightness and insulation levels. The 300mm of mineral wool insulation in the walls achieves a Uvalue of 0.14W/m2K, and roofs are even better than this at 0.13.
Additionally, the panels are all breathable, allowing water vapour to pass through the structure whilst maintaining the airtightness. This is
in contrast with most other SIPS systems on the market that tend to rely on non-breathable hydrocarbon based materials (such as PIR
insulation, plastic airtight membranes etc)
200x50mm
vertical studs
15mm OSB
board
Airtight barrier
50mm mineral wool &
50x50mm battens
25x25mm vertical
cladding rails
Prefabricated insulated timber frame panels
Walls U-value = 0.14 W/m²°C
50mm mineral wool &
50x50mm battens
200mm mineral wool
Breather membrane
Contract 2
2 - Superstructure - Pre-fabricated wall, floor & roof panels
Energy roof:
PVs
flashings
In addition to erecting the main timber frame, the timber frame supplier will
include the following services in this contract:
Supplying and laying of the thermally massive Coolvault floor blocks,
Supply and install the timber staircase and all internal timber stud partitions
(excl. plasterboard linings)
Provide UV stabilising black Tyvek, protecting the external envelope from the
elements until the external cladding is complete.
Barge boards
Roof flashings
PVs
Roof ventilation
Supply and install Butyl rubber lining to waterproof the unheated solar loft.
Supply and fix the integrated solar P.V. ZEDroof onto rafters, complete with all
flashings and ancillary components to provide a fully weather proof roof.
Internal partitions
Finally, barge boards, fascias, and cement board soffits are included to finish the
roof.
Ventilation is provided to the ZEDroof through hit & miss ventilators at the eaves
& either a ridge ventilator or rooflights at the top of the roof.
Coolvaults
Soffits
around 10 Tons of
exposed thermal mass
Staircase
Timber frame panels
Staircase
Contract 2B
3 - External Windows & doors - sealing and 1st airtightness test
The timber frame supplier will also provide all the external windows and
doors, these will be installed on-site once the frame has been erected.
The will also form openings in the structure for MVHR, ASHP and any
other ancilliary services at this stage.
The windows and doors supplied with the frame are double glazed low E
timber windows from a leading Europeean supplier. With a U-value of
1.4W/m2K, they help provide a super insulated building envelope with an
extremely low heat loss. Brake pressed aluminium cills
Velux rooflights are also installed at the same time as the glazing.
Other services provided in this works package include:
Arranging Main power supply to the fuse board
Arranging MCS testing once the ZEDroof has been installed
air tightness test
Finally, once the external envelope is closed up, the first air tightness test
is then performed. This checks the integrity of the airtightness of the
external envelope.
Contract 3
4 - Heat-hub
week 5-8 :
The load-bearing insulated and airtight timber frame, which is made of prefabricated structural floor and wall panels is delivered to site and erected by our
approved timber frame manufacturer.
The timber frame manufacturer also includes in this work package: stairs,
windows fitted and sealed to airtightness line, terracotta floor blocks and
ZEDroof panels.
Once the timber frame is completed, the ZED heat hub can be installed. North
facing roof pitches and solid walls are all clad in UV stabilised black Tyvek or
similar creating a stormproof secure shell which will provide protection from the
elements until the external cladding is complete.
At this point the house can be handed over to you as a completed weathertight
shell & core, alternatively the Zero Bills Home company can complete the build
by including the finishing package in phase 4.
Contract 3
4 - Heat-hub
This contract includes all the M & E services which transforms the house into a Zero Bills Home. The
3 main components to this are: electricity generation using the ZEDroof, mechanical ventilation with
heat recovery, and underfloor heating and hotwater provided from an air source heat pump.
Firstly the ZED Heat-Hub is installed in the hub housing (which has already been included in the
main frame). Ducting and supply and extract grills are then installed, providing the ventilation to all
rooms.
The underfloor heating panels & pipework and controls (incl. acoustic underlay beneath) are
installed by the same supplier.
Controls & commisisoning and IEE certification will then be completed to sign off the ventilation and
space heating second fix.
Install consumer units will then be installed, and the PV array is wired and commissioned by an
MCS accredited electrician.
At the end of this works stage, main power to the house can be turned on.
Handover of shell and core to the client occurs at this point for those who wish to
complete the build themselves.
Contract 3
4 - Heat-hub
Heat hub air intake
ZEDRoof:
Photovoltaic panels
Heat exchanger
Heat hub air extract
ASHP
Air extract
Hot water cylinder
Air supply
Underfloor heating coils
Air extract
Air supply
Underfloor heating coils
Contract 4
5 - External cladding & making good external envelope
week 8-12:
The external cladding, Roof tiles or slates, woodstove flue, kitchen and bathroom fit
out, are all included at this stage. First and second fix plumbing, drainage, electrics and
data along with plasterboard wall and ceiling finishes with a skim coat, and painting
complete the house. Finally the external works with the optional garage are completed.
The first three packages correspond to agreed milestones for mortgage funding release
stages.
Contract 4
5 - External cladding & making good external envelope
This works package provides all of the work needed to complete the
external finishes of the house. This includes:
From this point onwards you have 2 options: either you
commission the Zero Bills Home company to complete the build
entirely; or alternatively, you may wish to sub-contract out the
following works packages (or indeed complete them yourselves).
Flashing fitted
Supplying and fitting all the rainwater goods
Supplying and fitting external cladding (incl. insect mesh to all
ventilated air gaps) & forming the window reveals. A number of
different cladding materials are available for those who would like the
Zero Bills Home company to complete the build as one whole package
copings
Tiling is completed to the North roof pitch and North facing hanging
tiles. Finishing flashings (to North roof pitches), ridge caps and
copings are completed.
Juliette balcony (optional) are fitted where required
The canopy over front door is installed
Gutter
Juliette balcony
front door canopy
North roof & facade tiling
External cladding
Contract 4
6 - M & E 1st fix (excl. ZED Heat-hub) and 2nd airtightness test
Included in this works package are:
Internal drainage, Hot & Cold water distribution
Cutting holes in coolvault floor blocks (or other ceiling finish) and
ply for services etc
Cable & comms distribution
drawing tubes for co-ax, ariels and cables
Coolault holes
Sewage pipe
rainwater
Cold potable water
Hot potable water
Electric ducts
Kitchen
Toilet
Contract 4
7 - Internal finishes, M & E 2nd fix & Decorations
Internal linings and finishesare added at this stage, including:
12.5mm plaster board with skim finish to all walls (with timber skirting boards)
12.5mm plasterboard with skim finish installed to top floor ceilings
plasterboard returns to window/door openings with timber softwood cills
Plugs, switches & sockets
Light fittings
Wall tiles
Internal doors (including all ironmongery) are hung
15mm cement board is placed above UFH system installed in living spaces
tiles are laid in kitchens and bathrooms (a number of different options are available)
Sanitaryware is fitted in bathrooms as well as appliances, units and joinery in
kitchens.
Finally, plugs, switches, sockets, light fittings are fitted
including testing & IEE certificate
Cupboard doors
Appliances
Floor tiles
Cupboards
Appliances
toilets
Contract 4
7 - Internal finishes, M & E 2nd fix & Decorations
Install 12.5mm plaster board with skim finish to all walls
12.5mm plasterboard with skim finish installed to top floor ceilings
plasterboard returns to window/door openings
wall finishing
Plugs, switches & sockets
Light fittings
12.5mm plasterboard with skim finish
15mm cement board above UFH system installed in living spaces
tiles to kitchen and bathrooms (spec tbc) :
Bathrooms/WC's
Kitchen
All other areas
Provisional allowance
Finished internal walls
Bathroom suite
Wc suite
Wall tilling
Internal doors and Frames (760 x 2100) incl ironmongery
Cupboard doors (600 x 2100)
Skirtings
timber softwood cills
internal doors hung
Half bull nose SW timber skirting boards fitted
Plugs, switches, sockets, light fittings fitted
incl. testing & IEE certificate
Doors & frames
Skirting board
15mm Cement board
Bathroom, kitchen fittings
Units and carpentry built/ fitted
Appliances fitted
Meter boxs , control box housings fitted, BWIC
Finished house delivered
internal view - living room
Finished house delivered
internal view - living room
Finished house delivered
internal view - solar loft
Finished house delivered
Section
Finished house delivered
Facade customizations