Housing Site Layout Design.
Have you ever considered just how that estate you live on or worked on was planned, just how did it evolve from a blank piece of paper, what was the designers brief and how involved are the planners. I’ve seen seasoned old professional architects wither at the prospect of planning the larger site, the subject is something of a black art, and not for the faint hearted, the designers can be much maligned and trends come and go. Eddie Stevenson of Brookhouseconsulting.com who deal with housing schemes both large and small gives us an insight into the process.
Firstly a little background context is required. Generally a parcel of land is marketed and interested parties will evaluate the opportunity and submit sealed bids via a tendering process. Each bidding builder will need to know that their own product will work on the site and be assured that considering site constraints the scheme will deliver a yield in terms of saleable floor area. In the early nineties a benchmark of in excess of 11500sqft / acre was pretty much the baseline standard. At the height of the boom with a move to higher densities and three storey development a figure of 16500sqft / acre was the minimum standard. Greater densities are possible and 20000 to 30000 can be delivered with a mix of dwelling types. This explains the recent gold rush for apartment schemes, but that’s a different story. The rules of this game are the highest bid wins, the highest bid will be related to efficiency of the proposal.
So you are a designer working for a developer who normally has his own preferred product. You may receive a mix of housing to work to. This can be very prescriptive with exact percentages of each type to be provided. There will also be a percentage of social housing plots to be provided dependant on the total numbers achieved. In basic terms you need to consider the constraints and opportunities that the site offers. So you go to the site and walk it, smell it, take it all in, check the access for visibility, levels and obstruction, check the rise and fall of the land, observe the position and condition of any existing trees. Other observations relate to wildlife habitat, noise sources, environmental conditions, contamination, drainage opportunities, under and over ground services. You are looking for good views and ways you can relate to existing buildings, and the list goes on.
Before you start you need also to consider the local planning policy requirements and any peculiar highways requirements relating to car parking or numbers of dwellings serviced off a single point of access. There is no hard and fast national standards there can be over ten local plans belonging to individual councils in one county all with there own special policies and guidance. Other factors to be considered are the areas required for play space and general public open space. After this information gathering stage a survey base or more often than not, a large scale ordinance survey plan is obtained and we’re ready to start the design.
The Design Stage
At last you can get your pens out, and you need to make some fundamental decisions. A rough constraints plan will form the canvas for you to do your work. The first consideration is access, it may be obvious or you may have options. At this stage you will decide wheather to work with the surroundings, or if the context is poor you may opt for an insular approach. The entrance of the site is very important. The sales director, who has a senior position with your client will be focused on his site sales compound. Its always a good idea to give him an arrangement that delivers the sales centre with double garage and the “fly trap” so his customers can circulate around the show homes. The planners will be less preoccupied with such housekeeping but this is an essential element. I’ve been told more times than I can recall that the builder is a retailer, and it just happens to be houses that we are retailing. The site entrance is the shop window, it’s those first 20 seconds of the interview, it is important and will have to have representative house types from the main development.
Once into the body of the site, the position of open space to create the best possible public facility and be a focal point of the scheme is a prime consideration. The most efficient place for this will be at the end of the site, thus reducing the length of access road to dwellings. Sometimes a balancing lagoon to control rainwater run off will be required and will be sited in the open space, this will send it to the low point of the site or close to the storm outfall point. Play spaces need to be accessible and configured so as to avoid nuisance whilst maintaining surveyance, you need recycling space in gardens with rear access to it, and you want free circulation but you’re also supposed to be “secure by design” a catch 22 situation if ever there was one.
As a designer you have to make every plot saleable, but the emphasis is on the public realm, you aim to create areas of unique identity. You form squares, clusters, groupings, vistas, streets, footpaths and lanes. You need to look for exploit every opportunity to use the sites existing features be it retained trees and vegetation or other existing features. The importance of landscaping is not to be underestimated but some tight modern layouts can leave little scope. The main factors of a competitive layout likely to support a high value and therefore successful bid will depend on the land given away to roadway and circulation space. There will also be a squeeze on garden space, any over provision will be seized upon as wasteful. Front gardens are a luxury but it is still possible to design a quality environment. Very roughly speaking, for the built form you can go to an informal village style or a more formal structured approach or a mix of the two. Cars are also out of favour these days so they need to be concealed, out of sight and off the street frontage.
The first draft achieving target densities and taking into account all the parameters as described then goes on a journey. Firstly your client will circulate it around his directors and management team, they will all make comments. No one at this level will just sign the layout off, they will feel duty bound to make some comment. The scheme will be revised to address any valid issues raised. Then if the land is actually purchased the scheme will be submitted for planning approval and subjected to another round of “hurdles of subjectivity”. The proposal is circulated through the consultation process. The list of people consulted is a long one it includes: neighbours, the local parish council, local district councillors, the environment agency, archaeology, environmental health, the landscape department, ecologists, urban design, the conservation officer, highways department and any other interested parties. All of the above will make comments, a straight forward sign off is unlikely because everyone has an opinion and needs to be seen to be doing their job. The planning officer will assemble all of the feedback and from an opinion themselves on the suitability of the scheme. They will asses it against local and national policy. The design and access statement submitted with the application will promote the proposal in that context. Ultimately if all the boxes are ticked the scheme is revised as required and the scheme is approved to go on to the build phase, but then highways department can have another bite at the cherry through its adoption procedure to require revision.
I have simplified some of this process for this article I haven’t mention weighty design guide documents and design and access statements or the need for most houses to have southern aspect, or the new need to have the roofs pointing toward the sun for a set of solar panels or the implications of CDM safety regulations. Additionally some councils have very protracted pre application stages, and I mustn’t neglect to mention the vast raft of complex local and central government planning policy legislation.
It takes a long time to become accomplished in this niche skill and it’s a pretty thankless task. There is no grand unvieling and no round of applause. At every level, interested parties will be obliged to critique. There is no right and wrong just a subjective judgement in the eye of the beholder. The ultimate reward is way down the line when you finally get the site built out, and it looks right, feels right and people are happy to live there.