Outputs

A key early stage strategy was to develop a clear brief for the design of each developer’s house range. This was important to drive out early in the process. By doing this, it will prevent drift, scope creep and dilution of objectives, improving outcomes and bringing confidence in exploitation.

The design brief set out the principles to develop a house range. This included the following core elements:

Part 1: Design Brief

1. Background

2. Aims & Objectives

3. Purpose

4. IP & Scope Governance

5. Number, Type & Mix of Homes – Market Coverage

6. Budget, Timeframe and Work Plan

7. Exploitation Outlook

Part 2: Design Guidance

1. Compliance Requirements – Building Regulations, SAP & Overheating, Space & Accessibility Standards

2. Technical Scoping – DFMA, Standardisation, BIM

3. Design Boundaries – External Fenestrations and Internal Options

4. Future Proofing – NZC Homes, Fabric First, Heat Pump Ready

5. Information Required

6. Assumptions

As with any new product introduction process, it is crucial that the developers understood the affordable market requirements and how best to respond to these before housing design commences. The project had the benefit of having one of the UKs largest affordable homes provider as an active partner. L&Q provided great insight to the needs of the affordable housing marketplace, they shared the experiences of the differing nuisances and regional/client based needs, impacting on housing design, specification, and construction.

The research focused on the following main market research areas:

1. Engagement with G10 Group of large Affordable Homes providers

2. Engagement with smaller regional HA’s

3. Engagement with Affordable Housing Consultants

4. Engagement with Homes England.

5. Engagement with targeted HA’s via Online Questionnaire

Some of the key findings from the market research was:

1. Need for homes to comply 100% and up to 85%, with NDSS space requirements

2. Homes needed to include a wide range of tenure and occupancy needs

3. The bulk of housing centres around 2 and 3 bedroom homes

4. Bungalow and cottage flat options were needed, to add more range flexibility

5. The differences in specification preferences between HA’s

6. The differences in HFVN & NDSS reginal space standards, between England & Scotland

7. The preference for client options between HA’s

8. The grant funding thresholds, to provide cost targets, to design solutions

9. Indications of accessibility, user, and habitation usage requirements for all able and less abled persons

10. Homes need to be appealing, simple, robust, easy to use and maintain

The findings from the market research were invaluable, to inform the next stages of the Pattern Book development process. Several findings emerged that were not envisaged or considered.

In parallel with undertaking the market research, the developer partners, each undertook their own competitor analysis research. This was focused on the developers operating areas and where they are likely to meet competition. The purpose of this work was to establish good/bad practise and to better understand where competitors housing designs meets, exceeds, or falls short of meeting the affordable housing market needs. The research also undertook detailed house design studies, to better understand their compliance performance.

The findings from this research and detailed technical studies, provided the following high level findings:

1. Large variability in space standards, with many compliant and non-compliant house designs evident

2. Commonality of terraced design typologies, using 2 and 3 bedroom typologies

3. A split in internal habitation spaces & layouts, between front and rear facing homes

4. Lack of product variability, disabled friendly homes, bungalows, and cottage flat typologies

5. Large variety of room layouts, internal storage, and furniture configurations

6. Good and bad design principles and house typologies

7. Lack of preconfigured options, DFMA, future proofing and standardisation

8. Lack of plotting efficiency and considered terracing interfaces, impacting land and construction efficiency

Once all market research and competitor analysis were completed, the partners had a rich understanding of current marketplace solutions. The learning and data derived from this work, was critical in ascertaining the product mix required by each of the AIMCH developer partners. The scoping of the range was a vital part to determine and agree, before developing concept house designs.

The developers worked together to share thoughts on market needs, gaps, business preferences and the extent of the range to be created and managed by each developer.

The Affordable Homes Pattern Book, accommodation schedules agreed by the developer partners were:

1. L&Q House Range – 6 homes, predominantly 2 and 3 bedroom two storey accommodation, suitable for terracing and all homes 100% compliant with NDSS. Further typologies are planned to be introduced beyond AIMCH.

2. SMG House Range (Forest Collection) – 18 Homes, with a wider mix of 1-4 bedroom homes, with a broader range of typologies including bungalows, terraced and semidetached homes and two storey cottage flats, with arrange of 85%/100% NDSS compliant homes

Having finalised the house range and accommodation schedule, the process of creating concept designs was started. The design process utilised in-house expertise and third party architects, knowledgeable in affordable housing design to develop layouts, dimensions and templates that can be easily configured as terraces.

This process was intuitive and evolved over many iterations, as designed were challenged, tested, and refined following a process of internal review and assessment.

The concept designs centred around the following core design principles

1. Flexible, with internal and elevational options

2. Standardised & Optimised, for Cat 2 Panelised MMC system

3. Simple & Elegant

4. Functional & Compliant

5. Efficient, to Plot & Construct

6. Fabric First and Future Proofed

Following the finalisation and agreement of the concept designs for each of the developer house ranges, detailed technical studies evolved to demonstrate compliance to the next level of granular detail. An important consideration within the detailed design stages, is to ensure the homes comply with the requirements of NDSS (National Design Space Standards) in England and Wales, and the equivalent but different HFVN (Housing for Varying Needs) space standards in Scotland.

Key special and accessibility requirements include:

1. Gross internal floor area – relevant to bedroom and occupancy levels

2. Hall widths, door positioning and sizing, to allow free movement for a range of abled and less abled persons

3. Access requirements around fixtures such as beds, desks, and seating

4. Minimum sizing of furniture and fixtures within homes, to ensure adequate fit out and operation

5. Access ad space within wet room areas and head/foot of stairs

6. Provision for future disabled fixtures and fittings

7. Minimum storage provision, for cupboards and fitted kitchen units

This work leveraged the DFMA Guide developed by the AIMCH partners in the earlier stages of this workstream. The guide (available for download www.aimch.co.uk) provides guidance, advice, and solutions on the best way, to optimise the use of panelised timber MMC systems. The principles of the guide were fully adopted in the detailed design stages. This includes the early identification of loadbearing paths, joist spans and principle building services routes, to ensure simplicity of load transfer, construction and prevention of awkward detailing and structural clashes.

The key DFMA considerations built into the house ranges during the detailed design process:

1. Regular build form, no projections, and straight stairs

2. Joist and services to span front to back on narrow terrace designs

3. Loadbearing floor support point within middle third of homes – LB wall or down stand beam

4. All beams to be down standing to allow continuous oversale of floor cassettes

5. All brickwork fully supported down to slab level

6. No services, beams of stair trimming clashes

7. Principle horizontal and vertical services accommodated

8. Optimised panel heights to avoid cutting of sheathing and plaster boarding

9. Brick co-ordinated dimensions and openings

10. Standardised openings and full depth lintels to avoid beams in floors

A key design principle was to embrace standardisation within the final affordable homes pattern books being created. This built on the extensive standardisation studies and product family recommendations, derived in earlier stages of this workstream. The findings from this work can be downloaded from www.aimch.co.uk .

The key areas of standardisation were:

1. External Apertures – windows and doors

2. Stairs

3. Wet rooms – bathrooms and GF cloaks

4. Plot depth and brick coursing

5. Building heights

6. Roof lines

7. Optional gable window – preconfigured locations

The AIMCH developers’ partners have seen significant benefit in embracing standardisation and there is increasing opportunity for further collaboration across developers, as has been the case in the car industry, where common product families can be used across a broad church of housing developers, improving productivity at a sector level.

Having evolved the concept designs, DFMA and Standardisation elements for each home, progressively over 3 or 4 working iterations, the finalised designs were reached. This was a key milestone for each of the AIMCH developers. This marks the end of the development stages and the transition to the next stage, of detailed production design, information generation and compliance refinement.

In conclusion, final designs have been agreed and signed off by senior business stakeholders for SMG and L&Q.

The final house ranges are summarised below:

1. L&Q House Range – 6 homes

a. Predominantly 2 and 3 bedrooms

b. Two storey accommodation, suitable for terracing

c. All homes 100% compliant with NDSS.

d. Further L&Q typologies are planned to be introduced beyond AIMCH.

2. SMG House Range (Forest Collection) – 18 Homes

a. Wider mix of 1 to 4 bedroom homes

b. Two storey accommodation, suitable for terracing

c. Broader range of typologies including bungalows and cottage flats

d. Homes offer 85% and 100% NDSS compliance

e. The range is designed to meet 100% of SMG affordable homes requirements

After achieving the sign-off of the final designs, the process of creating detailed production information can commence. This built on the previous AIMCH BIM Housing Guide, developed earlier in this workstream, by the AIMCH developer partners. BIM (Building Information Modelling) is a process which digitises information, through using 3D design software and a BIM enabled process. Many housebuilders already use BIM and 3D modelling to produce their detailed technical and production information for their housing designs.

SMG and L&Q are late BIM and 3D design software adopters, AIMCH presented a real opportunity for both developers to leverage the content previously created and use their affordable homes pattern books, to learn and accelerate transition to future BIM adoption within their business.

The creation of the full suite of BIM Affordable Housing models will continue beyond the AIMCH project completion. Each partner is committed to complete all designs, modelling and production information in readiness for deployment, use and exploitation from Spring 22.

The final part of the process will be to complete Product Manuals, in the form of Pattern Book for governance and management within each developer.