This extension in Cirencester, by Roger Gransmore Architect, looks modern because of the use of glass but the design, form, proportions and main building materials are traditional and in keeping with the period. The extension is also slightly smaller than the original building.
In this kitchen extension in Henley on Thames by Trevor Bownass & Co, the design criteria of the historic building was replicated successfully, the proportions and shape of the addition and the materials are in keeping with the original building.
2. Proportions
It is often difficult to point at what it is that makes a building look good but intuitively, we know when buildings feel ‘right’, this is because they are proportioned. Good proportions are more easily achieved when designers apply a clear measuring system that establishes mathematical relationships between the parts. This traditional approach to designing ‘in proportion’ can help rationalise façades, making buildings more legible and easy to interpret.
Contemporary architecture is designed using decimal metric systems, as opposed to the historic imperial approach. This needs to be considered when designing new façades next to historic buildings to ensure proposals are in proportion with their setting.
For this reason, it is good practice to understand the proportions of adjacent buildings and to fully consider the whole streetscape proportions before arriving at a proposal. In classical architecture, the dimensions of all the component parts of a building or façade and the separation between components, follow a mathematical rule. Good contemporary design also applies these principles.
Good designers emphasise the relative hierarchy of some of the components over others, for example the entrance. Proposed extensions should never overpower the importance of the existing building or its main features.
Design Criteria
2.1 The extension is smaller than the original house. It is narrower in width, shorter in depth and lower in height than the existing property.
2.2 Proposed extensions do not spoil the immediate outlook from an adjoining property.
2.3 The proportions of the proposals are informed by the proportions of the immediate surrounding environment.
2.4 Proposals are formed by component parts that are in relation to each other in terms of size, position, and separation, and they follow specific and clear mathematical rules.