About AER - Building Performance Cymru

AER Building Performance Cymru is an independent consultancy providing SAP assessments, airtightness testing and sustainable drainage design for projects across Wales.

Led by Chartered Architectural Technologist Dafydd Morgan, an Elmhurst-approved On Construction Domestic Energy SAP Assessor (OCDEA) and Level 1 Airtightness Tester, AER supports architects, developers, housing associations and self-builders with practical technical advice from early design through to project completion.

Dafydd Morgan MCIAT

With a strong background in architectural design & technology, I understand how design decisions, construction details and regulatory requirements come together as a project moves from drawings to construction. This helps me spot potential performance and compliance issues early, before they become costly or difficult to resolve on site.

I provide clear, practical advice based on how buildings are actually constructed—not just calculations and test results. I work closely with architects, developers, builders and clients to find sensible, buildable solutions and help projects progress smoothly from design through to completion.

As a CIRIA-trained practitioner, I also specialise in practical SuDS design and SAB applications for new homes and small developments across Wales. I provide buildable SuDS drainage solutions that respond to site constraints, regulatory requirements and long-term maintenance needs.

Based in West Wales, I offer services across the majority of Wales, with travel costs tailored to each project location and scope.

Planning a project?

Contact AER to discuss your project requirements, programme and the most appropriate level of support.