This is divided into five parts:
The Design Challenge - We had to design an affordable home of unparallel quality and high thermal efficiency from sustainable and environmentally friendly materials to meet the needs of the modern day family.
Structural Insulated Panels (SIPs) offer fast-track, lightweight building solutions for all sectors of the construction industry. SIPs are ideal for all types of buildings as they offer a cost effective approach and are quick and easy to use. Panels are manufactured using high-pressure foam injection to create incredibly strong Structural Insulated Panels that can be used as wall, roof and floor panels to create highly efficient structures.
The term 'PassivHaus' refers to a specific construction standard for residential buildings which have excellent comfort conditions in both winter and summer. These principles can be applied not only to the residential sector as the name suggests, but also to commercial, industrial and public buildings. BRE manages the UK's detailed PassivHaus website.
are the world's leading standard in energy efficient construction are designed and built using a step-by-step approach use efficient components and a whole house ventilation system to achieve exceptionally low running costs are comfortable, healthy and sustainable
PassivHaus dwellings typically achieve a space heating energy saving of 90% compared to existing housing.
very good levels of insulation with minimal thermal bridges well thought out utilisation of solar and internal gains excellent level of airtightness good indoor air quality, provided by a whole house mechanical ventilation system with highly efficient heat recovery.
By specifying these features the design heat load is limited to the load that can be transported by the minimum required ventilation air. Thus, a PassivHaus does not need a traditional heating system or active cooling to be comfortable to live in - the small heating demand can be typically met using a compact services unit which intergrates heating, hot water and ventilation in one unit (although there are a variety of alternative solutions).
the total energy demand for space heating and cooling is less than 15 kWh/m2/yr treated floor area; the total primary energy use for all appliances, domestic hot water and space heating and cooling is less than 120 kWh/m2/yr
These figures are verified at the design stage using the PassivHaus Planning Package.
The purpose of ventilation is to provide clean good quality air by removing the stale, polluted air from our homes. The main task is, of course, to ensure that the indoor air is healthy and safe to breathe. Ventilation today is also about energy, and saving energy costs by adding heat recovery and/or renewable energy to the ventilation system.
PassivHaus
Standard Enkelt
LivingTM standard
construction UK
new-build common practice Compact
form and good insulation: All components of the exterior shell of a PassivHaus
are insulated to achieve a U-Value that does not exceed 0.15 W/m2/K. A
combination of modern methods of construction for our exterior shell of walls
& roof provide a u value of 0.15 W/m2/K Limiting
U-values of approximately 0.25-0.35 W/m2/K Southern
orientation and shade considerations: Passive
use of solar energy is a significant factor in PassivHaus design. Enkelt
Living restricted to site conditions and planners wishes while building in
restrictive sites, but will fully consider south facing when the opportunity
arises. Some
consideration is given with regard to north/south orientation, but the
improved energy savings resulting from passive site design are often
overlooked. Energy-efficient
window glazing and frames:
Windows
(glazing and frames, combined) should have U-Values not exceeding 0.80 W/m²/K,
with solar heat-gain coefficients around 50%1. Timber
framed windows argon filled double glazing units at 1.1 W/m2/K
are the best we can achieve and still produce an affordable product. 1.8-2.2
W/m2K
typical Building
envelope air-tightness:
Air
leakage through unsealed joints must be less than 0.6 times the house volume per
hour (this is the equivalent of an air permeability value of less than 1 m3/hr/m2 @ 50
PA). Tests are still to be carried out but all joints in
sips are double sealed with polyurethane foam and adhesive. Building is then
silicone sealed from inside, therfore we hope to achieve 1 m3/hr/m2 @ 50
Pa. Design air permeability of 7 to 10 m2/hr/m3@
50 Pa. This is approximately a factor of 10 poorer than the PassivHaus
standard. Research
has also shown that air permeability values for completed dwellings frequently
exceed these design limits. Passive
preheating of fresh air: Fresh air may be brought into
the house through underground ducts that exchange heat with the soil. This
preheats fresh air to a temperature above 5°C (41°F), even on cold
winter days. Fresh air is brought into the house through trickle
vents in windows and also from within the void space underground between the
solem and the underside of the floor which preheats the fresh air to a
temperature above 5°C The majority of new-builds do not achieve good enough
air permeability values to warrant the incorporation of a whole house
ventilation system - thus trickle vents, extract fans, or passive stack
ventilation is commonly used Highly
efficient heat recovery from exhaust air using an air-to-air heat
exchanger: Most of the perceptible heat in
the exhaust air is transferred to the incoming fresh air (heat recovery
rate over 80%). A mechanical ventilated heat recovery system that
operates at 70% efficiency is fitted in order to reclaim the heat from
exhausted air. Total
energy demand for space heating and cooling: Less than 15 kWh/m2/yr Exact figures will be unknown until air tests and
final assessment but we hope to achieve 22 kWh/m2/yr Typically 55 kWh/m2/yr
- Design Brief
- Structural Insulated Panels
- PassivHaus
- Heat Recovery
- Enkelt vs PassivHaus
The Design Approach - We carried out an exhaustive search to meet the demands of sustainable eco-friendly homes and to make full use of local employment opportunities and combined them with the basic principles of Scandinavian design.
The Design Solution - The solution was simple, we created open spaces with lots of natural light and we found the most modern and energy efficient materials available to ensure a new way of life that didn’t cost the earth! Construction guidelines were used from the BRE
(Building Research Establishment) for the construction of
passive homes.
We decided upon Structural Insulated Panels to form the frame of the building. Polyurethane Insulation is fused between two separate sheets of 15mm
sterling board, the wall panels are 150mm thick, inclusive of sterling boards, and the roof panels are 180mm thick, inclusive of
sterling boards.
Joints are filled with a expanding foam and faces are glued with an expanding polyurethane based adhesive. Joints are nailed every 50mm and internal joints wall joints are also sealed with a silicone sealant and achieve the highest form of energy efficiency. With the addition of timber windows,
with argon filled glazing units give us a u-value of 1.1 W/m2 K.
SIPs are an evolution of traditional timber frame building. Their composite construction ensure SIPs offer excellent structural load bearing, combined with superior insulation, whilst eliminating problems such as thermal bridging and compression shrinkage.
Recent government initiatives to encourage the building of energy efficient houses, and tightening of building regulations, have demanded that energy efficiency and fast, sustainable building methods be adopted across the UK.
Our chosen supplier is Hemsec SIPS, who offer a complete SIPs building solution, which not only minimizes waste and labour, but also exceeds all building regulations, and saves energy throughout the life of the product.
The Hemsec SIPS Building system has been extensively tested by CERAM, an independent UKAS approved facility, and is also approved by ZURICH Municipal, making a HEMSEC SIPs structure eligible for the Zurich Municipal Building Guarantee.
PassivHaus dwellings:
In Europe more than 7,000 dwellings, with a wide variety of designs, have been built according to PassivHaus principles.
Basic Principles:
A dwelling which achieves the PassivHaus standard typically includes:
For Europe (40o - 60o Northern latitudes), a dwelling is deemed to satisfy the PassivHaus criteria if:
It is also essential to follow a quality control procedure to avoid onsite problems which may prevent excellent levels of airtightness and thermal insulation being achieved.
Heat recovery captures waste heat energy and reuses it by returning it to systems or processes. This can include heating space and water.
The cost benefits of a heat recovery system depend largely on the type and scale of the installation, but heat recovery can give substantial long-term energy savings. It often reduces the need to generate heat in the first place, making further energy and cost savings.