Thursday, January 22, 2009

Luyanda Mpahlwa on MMA's design process for their Design Indaba 10x10 low-cost house

This text was originally submitted by Luyanda Mpahlwa to the Mail & Guardian in March 2008.
Architect Luyanda Mpahlwa writes about the process of creating and realising new housing solutions for the Design Indaba 10x10 Low-Cost Housing Project in Mitchell’s Plain, a development launched at Design Indaba 2008 in Cape Town.
Luyanda Mpahlwa admires the first completed MMA 10x10 house; the second is under construction behind him.
(Photo: Wieland Gleich -Archigraphy)
The brief
Last year the Design Indaba invited architects to design ten low cost houses on ten sites in partnership with ten international architects, for ten families. Our firm, MMA Architects, were paired with British architect Will Alsop and after a process of consultation and selection we were allocated a family in Freedom Park on Mitchell’s Plain. The Jonkers family stands to benefit from our design and in preparation we were issued by Design Indaba with a DVD documentary of the family. In it their profiles and wishes were conveyed. Due to differing design approaches however, the collaboration with Will Alsop had to be terminated.

The initiative is part of the development of Freedom Park by Niall Mellon Developers with 490 Units to be built. The brief for each Architect has been to design a house within the limits of the Government subsidy which allows a R50 000 allocation per household for a 40m2 house.

At MMA we set ourselves the objective of attempting to find a design solution that could make a contribution to the broader national debate on housing delivery. In our view Architects and Urban Planners in South Africa have not been involved in the roll-out of housing delivery as independent professionals. As a matter of fact, housing delivery although driven by Government, is largely being delivered by Developers. It is therefore fair to say that the non-involvement of Architects and Urban planning professionals in the housing delivery process has been to the detriment of this process, and has led to the neglect of urban quality of life. We feel that the Professional bodies involved in the built environment need to find creative ways to unlock the lack of involvement in this critical field of delivery in South Africa.

It was therefore important for MMA, in responding to the 10x10 Housing Project, to find solutions which also seek to address some of the challenges facing the country in the housing sector. These involve providing designs which offer dignified housing and quality of life in Freedom Park. We wish to address the quality of the low-cost house in general, while exploring possibility of sustainable and appropriate design.

There is obviously a need to achieve solutions that could increase the speed of housing delivery in general that would include innovative and alternative building methods.

Obviously this approach has gone beyond 10x10, and so we have broadened the scope of the brief. It became very clear early in the design process that the collaboration with Will Alsop was not going to achieve the desired results. The broader social considerations, and the response to the aspirations of providing a house for a “real family” which had specific needs, were not shared by the British Architects. Unfortunately, then, MMA pursued the design on its own. In the exploration and research which followed, at our Cape Town office we put together a team of four including principal architect Luyanda Mpahlwa, Uli Mpahlwa, Sushma Patel and Kirsty RonnĂ© to workshop the design parameters. RonnĂ©, the young Architect and designer was then allocated to drive the design process forward.
The row of 10x10 houses in Freedom Park, an artist's impression.
(Image: MMA Architects)
The process
Our main challenge has been to reduce the costs of the 10x10 house. We recognise that conventional building methods and materials are not going to achieve results and so alternative, more affordable building methods have been required. This is something very difficult to achieve in south Africa, given the dominance of bricks and mortar as the “accepted” way of building.

And given the fact that the plot sizes (112m2) were predetermined, our team has considered it necessary to maximise the usable area by minimising the building footprint as much as possible. A double storey unit was therefore proposed as the most land-use efficient option for our design. This approach posed further challenges with respect to the 40m2 limitation of the brief.

So a compact design evolved, on a limited footprint but with architecturally pleasing aesthetics. We have intended to create a positive urban quality and street edge layout. The building has been consciously located close to the street edge in order to maximise garden space at the back, and hard-up on the lateral boundary to create an outside garden and play area for the family. This design resulted in the location of the living, kitchen/dining and wet areas in the ground floor area which had a positive interface with the external spaces and garden.

The sleeping quarters are accommodated in the upper floor, allowing for some privacy and separation of potentially conflicting functions and uses. The main bedroom is located on the street edge, and has an external terrace which will provide relief from the tight internal spaces.

The children’s sleeping area is located toward the garden, providing four sleeping opportunities on double bunk beds. This design has resulted in a 54m2 house, which exceeds the 40m2 limitation. It is however a great achievement that despite the extra 14m2 provided, the costs of the house remained within the accepted cost limits.

One of the key considerations for the design, was that this would be a starter home, which could be developed as the family is able to afford it. The external upper terrace is the first opportunity for the extension to be realised. And on the ground floor, the house is positioned to allow for growth towards the back garden and yet still allow adequate space, including play space for the children within the safety of a private garden.
Sandbags packed inside the frame
(Photo: Wieland Gleich - Archigraphy)
The materials
The main considerations for a cost effective solution was to reduce the cost of building materials; reduce the building time and consider involvement of the community in the building process. After MMA research, and consultations with a structural Engineer, Henry Herring (Axis/AKi Engineers) and a Quantity Surveyor, Brian Mahachi (BTKM) the Ecobeam system was found to be the appropriate response for the MMA objectives for the 10x10 house. This structural system, developed by Eco-Build Technologies in Cape Town, consists of a timber structural frame combined with a sand-bag construction as in-fill for the walls of the building. The timber beams have metal inlays to provide tensile strength and thus improving the structural integrity of the system.
The sand bags provide excellent thermal mass qualities for passive thermal control. One of the many qualities of this type of building technology is that the “Ecobeam System” exhibits tremendous thermal stability, tapping into the indigenous building techniques that made the traditional buildings thermally sound and comfortable to live in.
Anybody who has lived in a mud and wattle rondavel, or old stone houses will know this effect. The occupants will be kept cool in summer and warm in winter.
The system also has excellent sound absorbing properties which help to provide a measure of privacy in close quarter living. The “Ecobeam System” with sand bag infill is much heavier than brick construction and is therefore wind resistant. The “Ecobeam System” resists water penetration due to the fact that the sand in the bags is a filter medium – any water penetrating the plaster will simply “filter” down to the damp-course and exit the wall to the outside.
This unique system is suited to mass production and will provide excellent job opportunities and skills development for the local community of Freedom Park, it is locally produced, simple to construct and favours unskilled labour especially the women in the community. In terms of cost saving, no bricks lie around the site before, during or after completion, thus eliminating "site-clearing", which is a major cost factor on any building site. The loss of building materials through wastage and theft is also reduced drastically.
The construction is primarily manual, with little or no need for electricity in both the production of the EcoBeams and in the construction process. The sandbags are plastered over in the exterior, and therefore, the only "wet" trade required is the plasterer. The plaster adheres easily to the sandbags and chicken wire that covers the walls. The Ecobags are made wet before the plastering process. The wet bags behind the plaster enable the plasterwork to "cure" instead of merely drying, as it does in standard construction. The end result is a very hard and reinforced cement finish.
In order to reduce costs for the 10x10 house, the interior walls are finished with timber boarding over the sandbags and some segments of the exterior walls are finished with timber boarding and translucent polycarbonate sheeting to maximise natural light penetration. Timber window frames areas and doors are provided by a custom made frame system developed by EcoBeam Technology.
In a nutshell, MMA and the Team were able to produce a 54m2 10x10 house for a maximum cost of R65.000 – R70.000. Although this cost exceeded the R50.000 budget, Design Indaba accepts that there is a factor of economies of scale. This factor was agreed to be approximately 15% since the costing of a 10x10 house was for a single unit. Therefore, when compared with the production of 1000 subsidy houses by developers the economies of scale come into consideration and as such these values should be compared on that basis.

Another benefit for the Jonker family is that the R65.000 house includes EcoBeam frames which are provided for future extensions, and which can be part of the landscaping meanwhile, for plants or creepers to grow up the lattice as shown in the diagrams. It is our view that this kind of thinking needs to factored into the subsidized housing delivery process, thus promoting the concept of starter houses into which the families could grow. MMA is proud to be associated with the 10x10 initiative, and the principal Luyanda Mpahlwa would like to see this as a worthwhile contribution to the national debate on sustainable and dignified housing delivery in South Africa.

**Please Note: Some of the design intentions could not materialise, and we had to cut costs further during construction and some of the initial design intentions had to be excluded, e.g. the future extension frame and the transitional entrance stoep. So some of what I wrote here that time has now changed a bit.**

Luyanda Mpahlwa MMA

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