There are three main types of access to flats. Core, deck or balcony, and corridor access. A superior type of corridor access flat known as the scissor maisonette, is described elsewhere in this blog and has its own page.
A core is a vertical shaft within a building, containing stairs, or stairs and one or more lifts. These are most noticeable from a distance when the lift machinery room(s) may been seen on top of the building at intervals along it indicating the position of the lift shaft and the staircase.
Core access has the advantage that it results in few flats per landing which is then easily supervised by the residents and at low risk of crime or anti-social behaviour because people know one another and the area is closely monitored.
Where two flats are accessed from a landing then they will be dual aspect and where four flats are accessed they may be single or dual aspect in a rectangular block and in a point block will be dual aspect having windows on adjacent sides of a corner, or in more advanced blocks with projecting wings (Upton Park Newham) may in the best cases have light from three sides as with these butterfly blocks on the Romford Road in London.
This is taken from Living at superdensity:-
Grouping between four and eight flats around a single core makes good use of lifts and allows at least some homes to be dual aspect. It also tends to be more space efficient (in net-gross floorspace) than double-banked corridors. Well designed cores can be easier to manage and more secure than corridor or deck arrangements. This core access model is generally the most successful.
How much better to put two or more cores in and make all the flats dual aspect?
These flats are reached from a balcony or gallery and benefit from light front and back, the only disadvantage potentially being overshadowing of the front door and kitchen window by the balcony above depending on the design, these work better with maisonettes where the balcony or deck is only built at every second level (see second photo below).
Balcony or deck access to flats in Churchill Gardens Pimlico
Balcony or deck access to maisonettes at Churchill Gardens Pimlico
In this photograph the lift machinery room is visible at the top of the picture above the stairs.
This typology is less successful in my opinion when built as an enclosed courtyard with a roof such as at Bolanachi in Bermondsey where the interior is no longer ventilated as well as would be the case were this a pair of free standing blocks open to light and air on both sides. Nor am I convinced that as much light is able to reach the front door as is the case at for instance, Churchill Gardens.
This courtyard approach appears to be popular with developers for reasons (I suspect) to do with the security offered by access control to the glazed interior. The trouble is that all the residents are then living in what amounts to a lobby or atrium. Give me the light and air of Churchill Gardens any day.
Corridor access will be familiar to anyone who has ever stayed in a student block at college or in a hotel. A long corridor runs along the centre of a rectangular building with rooms off each side, sometimes known as a double loaded corridor, where in the case of hotels the rooms will inevitably be single aspect and sometimes apartment blocks are constructed in this way for economy.
This is taken from Living at superdensity:-
In superdensity schemes this usually means double-banked corridors with all flats being single aspect, except on corners. The longer the corridor, the more cost/space-efficient the layout, because all can be served off one main core plus an escape stair. This may be acceptable where the orientation of the block avoids a north-only outlook, and views from either side are not compromised. Long corridors can be improved by daylight and view at each end and by good quality interior design and lighting. However, the practical and psychological disadvantages of single-aspect flats and long corridors are obvious . . .
It is worth noting that at Woods House while the developer has avoided a north-only outlook they have compromised the view to the West which is taken up by Bramah house.
The three types of access are described at some length in the following document produced by Design for homes in Section 5 “Organising and accessing flats”:-
Not all developers take the trouble to ensure that a dwelling has light and air from more than one direction. During the C19th and as late as 1937 in Leeds, back-to-back houses were still being built (like caves with party walls on three sides) as opposed to “through houses” which we know as terraced, with a small yard or back garden. Yet even today it is apparent that planning departments pass applications for single aspect flats off double loaded corridors for social housing.
Further reading . . .
Alice Coleman on the design of estates:-