new homes construction overview to code 4 long meadow, diss mark hart divisional construction...

New Homes Construction OverviewTo Code 4

Long Meadow, Diss

Mark HartDivisional Construction Director

How to get to Code 4• Carefully considered design to suit the location and

existing facilities• 100mm CFC interlocking insulation to ground

suspended slab• Bespoke timber frame system• Hemcrete insulated walls and Hemp fibre roof

insulation• Air source heat pump heating and hot water• Mechanical Ventilation and Heat recovery• Airtightness to 3• Life time secured by design• Fully recyclable materials

New Homes overview to Code 4 - LONG MEADOW - DISS

Site• Longmeadow, Denmark

Lane, Diss, Norfolk• 1st phase of 29 new

homes of a 3 phase development of 114 – 2, 3 & 4 bedroom homes

• Traditional sub-structure with bespoke timber frames for Hemcrete product

• Element of affordable housing supported by grant funding


Hemp Material

• Grown locally to development and processed at Halesworth

• Grows fast from seed to 4 metres within fourteen weeks

• Consumes C02 during growth

• Strong and very good insulator once processed


Pre planning

• To integrate various works

• Scaffold• Services• Cranage• Timber frame• Airtightness• Life time products


Sub-Structure• Typical sub-structure as used

on most housing sites• Trench fill concrete foundation

with brick and block to over site level

• Overall size to suit timber frame and Hemcrete = 300mm

• Standard drainage and services

• Concrete Beam and interlocking polystyrene blocks create fully insulated floor structure

• DPC & DPM covers complete oversite


Scaffold• Bespoke scaffold for timber frame

and Hemcrete


Roof structure

• Erect roof trusses in position on the sole plates at ground level

• Remove to adjacent level storage


Timber Frame

• Erect ground floor timber frame, – which is pre-constructed to

suit the Hemcrete product,

• Internal multipro board as internal shutter

• Floor cassettes, • Followed by 1st floor

timber frame • Lift finished truss

structure into position


External Services

• Fix all external services, ducts and boxes, any timber back ground must be fixed ready for all future external structural elements, such as balconies or porch roof structures, with all penetrations carefully sealed for air tightness


Formwork• Erect two sections light

weight plastic form work to external substructure brickwork– ensuring precise

dimensions – level and plumb

• Fixed into position with spacers and bespoke fixing screws

• Timber battens are fixed to the timber frame at each level to create stability between Hemcrete and timber frame


Hemcrete Installation

• Hemcrete is batched and mixed on site

• Hand poured into the shutter at approx. 600 layers,

• Shutters are removed from lower level and used to continue as works proceed

• Seamlessly installed around the complete envelope of the building

• Contributing to an airtight insulated shell


Curing Process

• Once cured after 1-2 days shutters are removed to expose a firm tactile structure

• which will need to fully cure over the following 4 weeks or so – according to weather

conditions,

• Once cured a robust shell is created


Internal Services

• During the Hemcrete stage internal services and fit out are carried out

• Followed by window and door fixing

• Fully seal all penetrations


Roofing

• Roofing and roof lines are completed once formwork is removed

• Loading of the roof tiling needs to be delayed to allow shrinkage of timber frame and Hemcrete

• Hemp insulation quilt is laid to the roof void areas


Rendering or Cladding

• Once full drying of the Hemcrete has been achieved and all apertures solutions are fixed, rendering or cladding can be finalised


Airtightness• Airtightness requires careful management• All construction stages from DPM to pre-

plastering need to be carefully completed• Airtightness barriers installed as design• All service penetrations need to be fully

sealed • Airtight sealants applied to window and

door apertures prior to plastering• Sealing around window boards and within

service voids are important


MVHR• Fresh outdoor air is taken into the Mechanical

Ventilation & Heat Recovery System which then passes through the filtration system to reduce the incidence of pollen and dust.

• Air removed from the house is passed through the HRV System to 'transfer' the heat to the Air taken in from outdoors, before being passed to the outside

• The heat exchanged warm air taken from outdoors is then carried to specific rooms

• Condensation from poorly ventilation rooms and smells are taken from rooms (i.e. Kitchen, Bathroom, Toilet) to be dispensed outside.


Electric Air Source Heat Pump

• Mitsubishi Ecodan domestic models installed • Provides space heating and hot water for all

the household needs• Captures ambient heat from outside air and

upgrades it to useful temperatures for heating hot water and radiators

• Best performance in well-insulated homes connected to underfloor heating

• As the insulation and air-tightness of the property are at a very high level, the house design is ideally suited for the heat pump


Conclusion• Design elements need to be selected to suit the location • Hemcrete has excellent insulation properties, with limited additional on site requirements• Timber frame is similar in design as traditional, but bespoke to suit the construction• Careful pre-planning is required to ensure seamless installation on site• Scaffolding requires careful adjustments to give safe working platforms as works proceed• The drying process of the Hemcrete and the lime render is subject to weather conditions• Airtightness is an important element• Triple glazed windows and doors, secured by design and lifetime certified• MVHR units ensure additional energy savings and comfortable air circulation• Electric air source heat pumps provide single source energy effective heat solution• Once completed the structure provides a practical, environmentally friendly alternative

to traditional masonry built structures, creating a peaceful, comfortable and economic living environment

• Recycling ethos is embedded within the whole concept• Bring on Code 5 & 6


I am happy to answer any of your questions. I will also be available to answer your questions after the

presentation.


new homes construction overview to code 4 long meadow, diss mark hart divisional construction...

Documents

long meadow diss slide

hemcrete new homes overview

position new homes overview

important new homes

shrinkage of timber

hemcrete installation

floor timber frame lift

bespoke timber frames