Housing Density
How do you calculate the density and mix of a site without requiring a site layout plan?
By using the information in the Housing Density manual you will be able to predict what sort of unit mix can be delivered at different densities, as well the level of density that can be achieved with a variety of different unit mixes.
Understanding density is fundamentally important and the earlier in the design process the better. Density is measured in a number of different ways at different stages of the design development, which frequently causes significant issues. The density manual will help you to establish a viable density for your site at the earliest opportunity, usually when considering a site for development (not after it has been purchased) and you will have a robust set of figures based on a well considered set of criteria. A viable density will give you a total number of units, houses and apartments based on your preferred mix of unit types and the net area of your site.
Density = +60dph with 40% apartments
≈ 30% will need to be at least four storeys.
Density = 30dph
≈ 30% of the units can be detached.
To find the net density of a site, which is the only way to truly compare density on a like for like basis, you must find the gross site area and deduct about 40% to give a net site area (as a starting point only).
Why 40%? Take a look at all the masterplan examples, although they range from 100 % residential development down to 32% most of them come out at around 40%.
Density = 40dph
≈ 5% of the units can be detached.
Facts + Figures
Density = 45dph
≈ 25% of the units will be apartments.
10 DPH
There should be no difficulties in meeting policy requirements at this density unless the local authority have minimum density requirements
Units
Habitable Rooms
Coverage
Parking
Storey Heights
3 Bed detached
x̄ 100 sq m
6 habitable rooms
Per Hectare
10
71
1,543 sq m
Garage
2
Per Acre
4
29
6,722 sq ft
Garage
2
4 Bed detached
x̄ 158 sq m
7 habitable rooms
This density is appropriate for:
Medium to large detached properties
Double garages
Drives
Front gardens
Large back gardens
Incidental open space
Additional landscape
High values
Steep or level gradients
Sites with existing trees and hedges
Various SuDS options
5 Bed detached
x̄ 241 sq m
9 habitable rooms
Double Garage
6m x 7m
The Rules
1. Ensure that back gardens are in proportion to the footprint of the dwelling.
2. Ensure that there is additional landscape to add value.
3. Ensure that every dwelling has an attractive outlook to the front.
4. Ensure that each dwelling is sufficiently different to appear unique