Retrofit & Principal Designer

Overview

Want your designs to take thousands of homes off fossil fuels, not sit in a drawer? Domna is looking for an experienced Retrofit Designer who can also act as Principal Designer under CDM 2015.

We’re a leading UK retrofit and housing decarbonisation specialist working with social landlords and public-sector clients on large, funded programmes.

What you’ll do

• Produce PAS 2035-compliant retrofit designs for whole-house and fabric-first schemes: EWI, IWI, loft, cavity, ventilation, heat pumps and solar PV.
• Take the Principal Designer role on our programmes: plan, manage and coordinate health and safety through the pre-construction phase.
• Work alongside Retrofit Coordinators, Assessors and site teams to turn assessments into buildable, compliant, safe designs.
• Keep design risk, buildability and moisture risk front and centre on every scheme.

What you’ll bring

• Proven retrofit design experience on domestic programmes, ideally social housing.
• Recognised Retrofit Designer competence (e.g. Level 5 Diploma in Retrofit Coordination and Risk Management, or equivalent route under PAS 2035).
• Experience acting as Principal Designer under CDM 2015, with a working knowledge of the Building Safety Act 2022 duty-holder regime.
• Strong technical knowledge of building fabric, thermal bridging, ventilation and moisture risk.

About Domna

Domna is a UK retrofit and housing decarbonisation business. We work with housing associations, local authorities and public-sector clients to make homes warmer, cheaper to run and lower carbon.

We operate as both Principal Contractor and Principal Designer. Our group covers principal contracting, PAS 2035 consultancy, EPC assessment, stock condition surveys, dMEV and loft insulation, and solar PV. It all runs on Ara, our own retrofit software platform.

We’re headquartered in London with an office in Preston, Lancashire.

Purpose of the role

The postholder owns the technical design of our retrofit programmes and discharges Domna’s Principal Designer duties on them. Every measure we install should be designed to PAS 2035/PAS 2030, safe to build, safe to maintain and free of unintended consequences.

The role combines two hats:

• Retrofit Designer — produces and signs off measure designs, details and specifications under PAS 2035, working from the improvement option evaluation and medium-term improvement plan.
• Principal Designer — plans, manages, monitors and coordinates health and safety in the pre-construction phase under CDM 2015, and meets the building regulations Principal Designer duties introduced by the Building Safety Act 2022.

Key responsibilities

Retrofit design (PAS 2035)

• Produce retrofit designs, drawings, details and specifications for fabric and systems measures: EWI, IWI, cavity and loft insulation, windows and doors, ventilation (including dMEV/PIV), heat pumps and solar PV.
• Translate Retrofit Assessments, the improvement option evaluation and medium-term improvement plans into buildable, compliant designs.
• Assess and design out moisture, condensation and interstitial risk; carry out or commission condensation risk analysis and thermal bridging assessments (psi-values) where needed.
• Design ventilation strategies that meet Approved Document F and PAS 2035 requirements.
• Ensure designs meet Building Regulations, PAS 2030, relevant BS/BS EN standards, manufacturer requirements and funding scheme rules (e.g. Warm Homes: Social Housing Fund, ECO, GLA programmes).
• Carry out pre-design site inspections and resolve design queries and variations raised during installation.
• Lodge and maintain design records and handover information in Ara and on TrustMark, as required.

Principal Designer (CDM 2015 and Building Safety Act 2022)

• Plan, manage, monitor and coordinate health and safety in the pre-construction phase of each project.
• Identify, eliminate or control foreseeable risks through design, and make sure other designers do the same.
• Gather and share pre-construction information with designers and contractors.
• Coordinate the Construction Phase Plan with the Principal Contractor and review it for adequacy.
• Prepare, review and hand over the Health and Safety File on completion.
• Act as building regulations Principal Designer where appointed: plan, manage and monitor design work so it complies with the Building Regulations, and cooperate with the Principal Contractor on compliance.
• Advise clients on …