Contractor

Name : Mike Whitfield Construction Ltd

Contact : Mike Whitfield

 http://www.mwconstruct.co.uk

Construction Manager

Name : Juraj Mikurcik

Contact : Juraj Mikurcik

Stakeholders

Function : Designer

Juraj Mikurcik

Contracting method

Other methods

If you had to do it again?

If we did the project again, we would give further consideration to the choice of material for foundations. The embodied carbon in concrete is high and there are some good alternatives available. We would also probably not install the wood stove, as we don't really use it very often, the capital could instead be spent on renewable technologies such as PV panels.

Building users opinion

The house has been a delight to live in since it was completed nearly 4 years ago. It it really easy to live with and a contrast to the previous home, which was uninsulated stone cottage. Being a passivhaus the energy demand for heating is very small. At the same time, the quality of internal air is excellent all year round thanks to the central ventilation system with heat recovery (there's automatic summer bypass). CO2 levels generally stay below 800ppm and air 'feels' fresh due to minimum amount of VOCs in the interior. Temperature is very stable, during winter it goes down to about 18C and never goes above 25C in summer, even during the heatwaves. Internal relative humidity is between 40-60%. The house is well daylit, generally there is no need to put the lights on during the day. Acoustics are excellent, will low levels of reverberation thanks to hit & miss batten ceiling in the main living space. Textured clay plasters on walls also help reduce the echo effect.

Energy consumption

• Primary energy need : 89,00 kWhpe/m².year
• Primary energy need for standard building : 89,00 kWhpe/m².year

Calculation method : Primary energy needs

Breakdown for energy consumption : Primary energy needs corresponds to Passivhaus PE value. heating approximately 1200kWh/a hot water approximately 2400kWh/ acooling: zeroventilation: approximately 200kWh/ alighting & other small power: approximately 900kWh/a

Envelope performance

• Envelope U-Value : 0,13 W.m^-2.K^-1
More information :

External walls consist of 400mm thick Ecococon prefabricated straw/ timber panels, externally clad with 60mm woodfibre board and ventilated timber rainscreen cladding. Internally the walls are plastered with 25mm clay plasters, adding useful thermal mass. Floor is exposed concrete slab, fully insulated under. This also adds useful thermal mass helping to slow the daily temperature swings. Floor u-value 0.135W/m2K. Roof is 400mm timber I-beams fully insulated with blown recycled cellulose insulation, u-value 0.093W/m2K. Corrugated steel roofing finish. Windows are triple glazed timber/ aluminium composite, passivhaus certified u-value 0.83W/m2K

• Building Compactness Coefficient : 4,60

Indicator : EN 13829 - n50 » (en 1/h-1)

• Air Tightness Value : 0,40
 Blower door test


Users' control system opinion :

The heating system consists of two towel rails running off the ASHP hot water cylinder, and a standalone wood stove. Towel rails are running off a pump with three modes (off, auto and 100%). 

More information

monthly average electricity bill approximately 80 Euro (this covers everything)

Real final energy consumption

Final Energy : 89,00 kWhfe/m².year

Real final energy consumption/functional unit : 47,00 kWhfe/m².year

Year of the real energy consumption : 2 020

Systems

Heating system :
• Heat pump
• Wood boiler
Hot water system :
• Heat pump
Cooling system :
• No cooling system
Ventilation system :
• Double flow heat exchanger
Renewable systems :
• No renewable energy systems
• Renewable energy production : 75,00 %
Solutions enhancing nature free gains :

High performance triple glazing allow solar gains whilst keeping the heat in during winter. In summer, the glazing is mainly shaded with roof overhang and external blinds, preventing unwanted solar gains and overheating.

Urban environment

Plot is at the end of existing village. There is a bus stop nearby, connecting the village to the nearest town of Hereford. Plot is also within cycling distance to place of work and the nearest town.

• Land plot area : 1 350,00 m²
• Built-up area : 8,00 %
• Green space : 1 000,00

Product

EcoCocon



Ecococon

[email protected]

 https://ecococon.eu


Product category : Structural work / Structure - Masonry - Facade

Prefabricated straw/ timber panel system. Highly efficient, it is a certified passivhaus component, also has Cradle to Cradle certification. Approximate cost 150 Euro/m2 of wall

Very enthusiastic about the product, it was the first application of the system in UK

Construction and exploitation costs

• Cost of studies : 3 000 €
• Total cost of the building : 150 000 €

Energy bill

• Forecasted energy bill/year : 960,00 €

Real energy cost/m2 : 10.11

Real energy cost/Dwelling : 960

Water management

• Consumption from water network : 110,00 m³

Water Consumption/m2 : 1.16

Water Consumption/Dwelling : 110

Indoor Air quality

Generally building materials and product with low VOCs have been used: timber and straw wall panels, self-finished clay plasters, low VOC paints and stains. Central ventilation system ensures the air is changed at the rate of 0.4 per hour.

Comfort

Measured indoor CO2 concentration :

between 450 and 800ppm CO2

Measured thermal comfort : indoor temperatures vary between 18C (coldest point in winter) and 25C (peak summer heatwave)

GHG emissions

• GHG in use : 16,50 KgCO₂/m²/year
Methodology used :

PHPP

• Building lifetime : 100,00 year(s)