- Details
- Written by: J C Burke
- Category: Buildings
- Hits: 29228
Basements for housing
Including a basement in residential developments helps maximises usage of available land, offers added value, more space and accommodation with additional performance benefits. Refurbishment or alterations to existing spaces below ground are also an effective way of providing additional habitable space to a property. It is possible to retrofit a basement under or adjacent to an existing property.
A basement story is defined within the Building Regulations of England and Wales as at least 1.2m below adjoining ground level. This aspect has implications for natural lighting and ventilation. For much deeper structures there are several other options to cover there two important issues.
Benefits of domestic basements include:
- Added value.
- Additional habitable or useful space.
- Increased floor area in locations with limited development potential above ground.
- Creation of flexible, adaptable space, due to creation of single span structure.
- Spaces with extra sound insulation, expanding range of potential use, including home working, home cinema or wine cellar!
- Spaces with good thermal mass and potential energy efficiency and cooling.
- Good stable structural base, capable of supporting heavy loads above.
- Resilience to local environmental effects in the soil, such as shrinkage or tree roots.
- Flood resilience solution, by raising habitable spaces above flood level while providing useful non-habitable storage space below.
Basement design
The appropriate design of basements is well established and achievable providing design and construction guidance is implemented.
Basement design process simplified:
- Establish current and anticipated future use of basement.
- Site survey and soils analysis including exploratory works.
- Design proposals to define type of construction water tight class, ventilation and thermal performances.
- Detailed structural design integrated with design of waterproofing/drainage.
- Utilities entry, Earth Pipes etc and construction waterproofing, detailing etc
Aspects of the design process are interrelated and a unified approach should be established defining roles and responsibilities of the design team. It is advisable to avoid complex geometries to facilitate waterproofing and to produce a three dimensional review of structure and waterproofing.
Basement construction
Reinforced Concrete is the most common and appropriate material used in the construction of new basement walls and floors. This is due in part to cost and availability but also its adaptability, inherent resistance to water, durability underground and ability to provide a stable structural surface for the support of waterproofing membranes. Options include masonry or blockwork, cast insitu, precast concrete, twinwall and insulating concrete formwork (ICF). The graphic shown has an insulated layer on the outside of the basement wall - however most practical is Insulated Concrete Formwork [ICF]
The method of concrete construction chosen will be influenced by the type of waterproofing protection permitted according to the water table situation and proposed basement use as described in BS8102 Code of Practice for the protection of below ground structures against water from the ground.
For further guidance on the benefits of basements for housing and principles of construction and design refer to Basements for Housing.
The publication ‘Concrete Basements: Guidance on the design and construction of in-situ concrete basement structures’ provides comprehensive guidance on the design issues for the design of deep basements, focusing on structural calculations.
Other useful resources:
- Details
- Written by: J C Burke
- Category: Buildings
- Hits: 13136
What are Passivhaus Standard Requirements?
The requirements for a home to meet Passivhaus Standards. The Passive House Institute detail these as follows:
- Space Heating Energy Demand should not exceed 15 kWh per m2 of net living space per year.
- The Renewable Primary Energy Demand, the total energy to be required for all of your home’s domestic applications, must not exceed 60 kWh per m2 per annum.
- For Air-tightness, a maximum of 0.6 air changes per hour is allowed at 50 Pascals pressure (ACH50). This will be verified with an onsite pressure test.
- Thermal comfort should be met for all living areas for energy-efficient houses in both summer and winter seasons. This shouldn’t exceed 25°c for any more than 10% of the hours in a year.
- The "fabric first" concept of making sure the property is heavily insulated, is paramount - and generally to a much higher standard than current UK Building Regulations.
See our detailed blog regarding Passive House Standards as defined in the US/UK CLICK HERE
The image indicates the mechanical ventilation system [red and blue circuits] - in this example the fresh incoming air has been routed under the basement to pick up some 'heat' from the earth [in the winter] and to cool this same air in the summer - "Earth Heat Exchanger" A further method to reduce the total energy requirement of this design.
Also indicated is the summer sun entering the building via the windows, with suitable shading {roof overhangs] to prevent over-heating in the summer. However in winter, the lower sun will penetrate deeper into the structure, thus giving a valuable solar gain in these colder months.
The Basement will also be used for rainwater harvesting - to be filtered and used for flushing toilets and even bathing and showering etc. Thus reducing the cost of drinking water into the property.
- Details
- Written by: J C Burke
- Category: Buildings
- Hits: 12271
Octopus Energy and a housebuilder have entered into a partnership to roll out the UK’s first homes to guarantee residents Zero Energy Bills. The construction of the properties was first announced in February of this year but now it has been revealed that Octopus Energy will be providing a bespoke tariff as part of the project.
These homes will come equipped with an air source heat pump, solar panels and battery storage technology. Alternatively they could also be additionally “powered by wind turbines and bio-methane powered CHP for district heating systems. Either way Octopus gets embedded power supplies with zero capital costs.
These energy efficient technologies will combine to provide “free”, clean energy around the clock, with Octopus Energy providing a tariff specifically for those living there. Octopus will also sell on the ‘surplus’ [over and above any battery storage] electricity so generated to its customers – as low cost power – thus averaging down their cost of electricity into the bargain
How many of the homes
There is no real limit to numbers in this important ‘marriage’ of construction and Energy partnership, just the finance and will power to encourage such schemes as ‘normal’.
Many of these homes will be “zero-carbon (dioxide)” in operation, meaning they can generate their own sources of energy {heating, Hot Water and Electricity], helping to reduce emissions produced by ‘normal’ domestic utilities such as electricity and heating. These concepts can also be extended to Commercial and Industrial properties.