Good medium-density housing design should cater to the transport, security and mobility requirements of each occupant.
When considering how people will use and access a dwelling, it is important to always keep universal design in mind. For example, those with special mobility requirements may require stepless access in certain areas of their housing unit, such as showers. Consider how other accessibility and security features will work in practice, such as handrails, mobility car parks, lifts and even the height of light switches.
Changing work patterns mean that some occupants now expect their home to also support their business activities or for their living and working spaces to be within the same building. The design of MDH developments should have provision to allow this to occur.
To achieve this, consider providing some housing units with an alternative entrance for business purposes and some additional parking for business clients and visitors. However, the development should take care to ensure that only compatible work activities are allowed to mix with living spaces. Activities that are noisy, smelly or operate late at night should be avoided.
Driveways, garages and parking
When designing for MDH vehicle access, consider how occupants travel (walk, car, bike, motorcycle, wheelchair) and the types of vehicles that will visit the site (cars, vans, removal trucks). Take into account the occupants’ level of car ownership, the need for loading zones and space for large vehicles such as maintenance trucks and off-street visitor parking.
At the same time, the design should enable pedestrians, cyclists and vehicles to interact safely. If it’s not possible to create a dedicated way for each mode of transport, at least keep vehicles and pedestrians physically apart. Consider using clearly defined and separate pedestrian accessways to each housing unit and other destinations, and ensure drivers have a clear view of the driveway and pedestrians.
Where driveways intersect with the street or cross footpaths, walkways and cycle paths, drivers require a clear line of sight and easily understood traffic signs. At the same time, limit the number of driveways and vehicle accessways that connect directly to the street. Too many access points, external parking and interrupted walkways can negatively impact the character of the area.
Avoid repetitious or monotonous garage doors on street frontages. Instead, place the garage for each housing unit in a different location and orientation. Where this is impractical, try grouping garages together, varying their offset or breaking up the space with entrances, windows, outdoor spaces, landscaping or other features.
Consider ways to slow down vehicles as they enter the development. This could be done with signage or using trees or road structure to create a perceived narrowing of the road. Consider adding an unusual texture to the road surface, such as with paving stones or speed humps.
Try to incorporate vehicle turning bays in areas of the development that are not commonly used by pedestrians, are away from habitable areas and cannot be seen from ground-level dwellings.
Where car parks are provided, they should be easy for occupants to access. Design parking to minimise the effects on occupants in adjacent units of vehicle lights, noise and fumes as well as overhead lights and garage doors. In some cases, acoustic isolation may be required.
Car park design
MDH developments, particularly those that incorporate multiple functions within the project (such as dwellings, retail and parking), require a number of potentially conflicting aspects of design to be resolved early in the process.
To illustrate a potential issue, consider an MDH building that has several storeys of dwellings located above a basement car park. To give all users of the car park access to their allocated spaces, the structural set-out of beams and columns for the parking area needs to allow for:
- designated parking spaces
- accessibility parking spaces (which are wider)
- a range of vehicle dimensions
- vehicle access into and out of the parking area
- vehicle access between floors (if the car park is multi-level)
- vehicle manoeuvring within the parking area.
The structural set-out of beams and columns also needs to be coordinated with the layout of the dwellings above. For example, the dimensions of each dwelling and the location of columns, inter-tenancy walls, fire walls and lifts are integral to the structural design.
Several guides detail suitable dimensions to achieve these requirements. AS/NZS 2890.1:2004 Parking facilities – Off-street car parking and NZS 4121:2001 Design for access and mobility: Buildings and associated facilities are referenced by Acceptable Solution D1/AS1 and provide useful guidance for parking design.
Size of car parking spaces
The number of vehicles a car park can accommodate is largely determined by the parking angle.
Generally, a shallower parking angle (nose to tail) allows for a narrower aisle and overall parking area width. However, a shallow design needs more space for adjacent spaces and therefore fits fewer cars in a row. Parallel spaces are the shallowest of all, but this design requires long spaces to allow room for vehicles to manoeuvre.
Similarly, a steeper parking angle (closer to 90°) generally allows for narrower adjacent spaces. However, a steep design needs a wider aisle to allow cars to enter and exit and wider parking spaces and fits even fewer cars in a row. Perpendicular spaces can accommodate more than twice the number of cars along the same length as parallel spaces.
For MDH developments that require a dedicated car park, locating it at ground level eliminates the need for access ramps, additional structures and waterproofing. However, where this is not feasible, parking access ramps (up or down) should have a gradient no greater than 1:8 (1 m vertical rise for every 8 m horizontal travel).
Remember to allow space for overhead services, such as lights, ducting and pipework, which may be suspended from the floor above.
It may seem obvious, but MDH must be as pleasant to live in as possible. This poses several challenges when dealing with higher-density living and occupants who may be more familiar with traditional stand-alone housing.
A most effective way to enhance liveability is to make it efficient and convenient for occupants to move around (plus ensuring privacy of individual units, letting in sunlight and providing an outlook). The design can do this by providing shared internal circulation that is simple and easy to follow. The route between each housing unit and the entrance to the development should be as short as possible, clearly defined and well lit. For larger developments, use features that help occupants maintain their bearings, such as exterior windows, ventilation, clear signage and small lobbies.
Internal circulation within housing units must also be efficient and well planned, especially within smaller units. Internal paths should be simple and direct and can be integrated into the living spaces provided privacy is maintained between key areas, such as bedrooms, bathrooms and entrances. When done well, this approach can maintain good separation between spaces while eliminating the need for most internal doors.
MDH developments should be designed to ensure occupants feel safe and secure.
One way to achieve this without installing intrusive security systems is incorporating natural surveillance. Natural surveillance allows people engaged in their day-to-day activities to observe the space and people around them.
Options include providing users of a communal space with a clear sightline to a car park or rear of a dwelling. This increases the security of the area by creating the perception of risk for potential offenders and can enhance feelings of safety for users of the space. Facing a number of dwellings towards a single communal space is a common way to increase natural surveillance.
While it is an effective way to improve security, natural surveillance should not compromise the privacy of the normally habitable areas of housing units.
Other security measures typically used for buildings also apply to MDH. It is good practice to provide the front entrance of larger developments with security lighting. Each dwelling should have lighting at the main entrance, screened safety doors, solid-core external doors and a peephole in the front door.