What is airspace development?
Airspace development is the process of building on top of pre-existing structures to make use of airspace in order to provide housing. It is an increasingly popular way to provide extra housing in built-up areas. According to recent research, up to 180,000 extra homes could be provided in London by building on current residential properties, helping to ease the impact of the housing crisis.
Why develop airspace?
As populations increase in the UK, space for housing becomes limited. Airspace development is an efficient way to build new homes without having to build on brownfield land which is costly to clean up or greenbelt land which is unpopular.
Undertaken responsibly, airspace development can offer a lot of benefits for residents who live in the property that is built on.
How much disruption is caused by airspace development?
It depends on the approach. At South Coast Estates we aim to use off-site construction techniques wherever possible which minimises disruption for residents and the surrounding area. Construction takes place away from the building. In most cases we will use cross-laminated timber, which considerably speeds up the building process.
What are the benefits of airspace development?
Benefits are multiple and varied with some of the most significant being:
- Helps mitigate the housing crisis without building on new land
- New roof installed with a circa 20 year guarantee
- The reduction of the building service charge
- Communal areas and other parts of the building will be refurbished
- The overall value of the existing properties will rise
Is it safe to build extra storeys on top of my building?
This is assessed at the earliest stage of the project. If your building does not have the structural integrity to make it suitable for an extra storey it would not be proposed for airspace development. A structural engineer will undertake a thorough assessment of your building to ensure it is safe to undertake work.
If the structural engineer deems the building incapable of taking the additional load the project will simply not go ahead.
How long will the development take?
The planning process is challenging and requires a great deal of input from various specialist consultants. Typically the planning phase can take between 4-12 months, and construction 6-8 months.
Will my service charge go up?
No, in fact your service charge should go down due to ‘economies-of-scale’. The newly developed properties will generally contribute on a pro-rata basis leading to a reduction of the overall service charge costs per flat.
How often will I be contacted and updated?
South Coast Estates are committed to being as open and transparent with existing residents as possible. We will hold regular meeting with you to keep you informed of a project’s status and answer any questions you may have.
Where possible we will work with you and take your requests into consideration when discussing things like renovations to communal areas.
How are water, gas and electricity supplies affected?
Services to existing flats will remain unaffected throughout the build process and on completion of the new properties. This is achieved by installing new risers from ground level direct to the roof.
Will external cladding be used?
In most circumstances South Coast Estates will not add external cladding to the property. If it were deemed necessary by engineering and building experts we would always consult leaseholders before cladding would be added.
It would only be suggested in scenarios where it would be of genuine benefit to the durability and efficiency of the building.
External cladding, as a rule, is not inherently unsafe. South Coast Estates undertakes building work to the highest of standards so if cladding were to be added you can rest assured that it would be fire-safe, insulating and of the highest quality.
Can we remain in our property whilst works are ongoing?
Yes, you will be able to remain in your property whilst work is undertaken. Before works commence we invest a lot of time in creating a construction plan that will be as convenient to existing residents as possible. This includes designing the scaffolding to allow for points of entry and windows not to be blocked. As many stages of the construction process will take place off-site, construction personnel will spend less time than conventional builders on-site.
Will my building be fire safe after work has taken place?
Yes, South Coast Estates take the quality of their builds incredibly seriously. We will always ensure your building meets and where possible exceeds all building regulations – it’s in our interest as well!
Will you be able to provide us with certifications and paperwork to assure us that the building will be safe?
On completion of the projects a raft of compliance documentation will be available including a 12 year professional Insurance indemnity provided by the Architects against the safe use of the building by occupants. What is more, all consultants involved in the project will hold high levels of Professional Indemnity insurance which enables them to execute their duties in a professional manner.
How do I know that the building works will be of a high standard?
South Coast Estates only develop the airspace of buildings of a freeholder to which it has a business relationship, meaning that unlike traditional developers, our priority is not to complete the new apartments as quickly as possible. The quality of the build ultimately affects the value of the newly developed flats as well as the freehold, so it is as much in our interest to complete a development to a high standard as it is the current tenants.
What kind of refurbishment works should we expect?
Each project is different, but at the early stages we will assess all requirements for improvements. Here are some of the things we will look at:
- Renovation of communal areas such as lobbies or entrances
- Renovating communal outdoor spaces
- Improvements to insulation and the exterior of the building
- Upgrading safety equipment such a fire alarms
- Upgrading security systems where needed
Will the value of my property be affected?
Due to refurbishment works we have seen an average of a 3-4% increase in the capital value of existing properties below the newly developed airspace. The considerable reduction of service charge costs coupled with the refreshment of the building’s aesthetics help to increase property values.
What is offsite construction?
Offsite construction relates to the assembly of elements, or units, of a building away from its intended permanent location. These partially built elements are then transported to the construction site, where final assembly and finishing is carried out.
Although far from a new practice, building off site is considered a modern method of construction (MMC), one that is being increasingly explored as a viable solution for reducing construction time, improving sustainable development and offering considerable cost savings.
What are the benefits of offsite construction?
There are a multitude of advantages to assembling elements of a building in a factory environment situated away from the building’s eventual, permanent location. These include:
- a significant reduction in construction time in comparison to onsite construction; in some cases by up to 50%
- the removal of mess, dust and noise from existing occupants or residents, thereby reducing disruption and protecting their living and/or working conditions
- the ability to store materials and elements of the construction where there is space to do so, since this may not be feasible in heavily built-up areas
- a significant saving in onsite working hours for construction workers
- improvements in the overall quality of the build, since the individual elements can be assembled to a greater degree of finish than they would under onsite conditions
- a substantial reduction in occupancy costs related to energy use, maintenance and repairs as a result of enhanced specification standards and build quality
To explore the advantages of offsite construction in further detail, please see our feature ‘Why offsite construction is taking the headache out of renovations for residents’.
Which parts of a building can be constructed off site?
In recent years, offsite construction has become increasingly popular, with the industry seeing greater use of sub-assemblies and components than before. The type of building elements that are most effectively manufactured and assembled off site include:
- prefabricated dormers
- timber I-beams
- prefabricated chimneys
- prefabricated plumbing systems
- door sets
- structural insulated panels (SIPs) – used in floors, walls and roofs
- cross-laminated timber (CLT) – also used as structural panels for floors, walls and roofs in mid-rise construction
However, it is possible for the vast majority of a construction project to take place off site, as was the case with the Leadenhall Building in the City of London, of which more than 80% was assembled in a different location.
What are the different methods of offsite construction?
A number of different construction methods can be used during an offsite project, and their selection will be dependent on the specific type, requirements and budget of the job. Examples of construction methods that may be employed include:
- frame and deck construction, where the structure is formed by a precast deck, supported by precast beams and columns
- crosswall construction, whereby load-bearing walls provide the primary vertical support for precast floors
- modular construction, which involves the production in a factory of three-dimensional units, or modules, which are then installed on site to form a uniform, cellular structure, such as a hotel or student halls of residence
Is offsite construction safe?
There are relatively few risks associated with offsite construction in comparison to building on site , since it usually takes place in controlled factory conditions. This vastly reduces the number of environmental dangers to workers, including adverse weather conditions and working at great heights. For these reasons, it is considered far safer to manufacture and assemble buildings off site.
How long does offsite construction take?
As with any major construction project, the timescale of works is likely to be in months and weeks; however, there are significant time savings to be made with an offsite build in comparison to traditional onsite construction methods – typically 30% to 50%.
For example, the Stack Apartments in New York, the city’s first building made entirely of modular units, was erected in just 19 days following the modules’ shipment to the site after their construction in Pennsylvania.
Where does offsite construction take place?
By its very nature, offsite construction means removing some of the major elements of a build project from its intended final site and placing it in a controlled environment. This will typically take place in a factory or similar location.
How many buildings are constructed off site?
Despite experiencing a recent surge in popularity, offsite construction has actually been employed from as early as Roman times. While definitive figures are difficult to gauge, there has been a marked increase in recent years, particularly in the use of modular construction – one offsite method. A well-known example is Heathrow Airport’s Terminal T2A, for which the deployment of modular mechanical and electrical systems is thought to have saved as many as one million onsite working hours.