The Zero Bills Home company offers you the opportunity to complete your home through a number of self-contained works packages. Package 3 provides the basis of an energy positive home.
1) On-Site Infrastructure and civils (week 1-3)
Off plot roads, communal services (i.e. water, electricity and data), site infrastructure, drainage, highways and landscape plus services to plot boundary are installed by your local groundworker.
2) Foundation and ground floor slabs (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, sub-slab insulation, and smooth ground floor screed are installed by an approved groundworker company (such as Roger Bullivant’s or equivalent).
Or alternatively, you can organise your own foundations and ground floor slab construction.
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
An external blockwork plinth & perimeter ground beam ready to receive the timber frame wall panels above.
3) Superstructure - Pre-fabricated wall, floor & roof panels External Windows & Doors
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 U-value of 0.13W/m2K, and roofs and floors are even better than this at 0.1
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.)
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.
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 weatherproof roof.
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.
The windows and doors supplied with the frame are double glazed low E timber windows from a leading European supplier. With a U-value of 0.9 W/m2K, they help provide a super-insulated building envelope with an extremely low heat loss
Translucent building integrated ZEDroof generates annually more electricity than needed.
Velux rooflights are also installed at the same time as the glazing
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.
4) Finishing package (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.
This works package provides all of the work needed to complete the external finishes of the house. This includes:
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
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 the front door is installed