Design Engineer – Renewables

Company: Unify
Apply for the Design Engineer – Renewables
Location: Cardiff
Job Description:

Renewables Design Specialist


Location: Cardiff


Salary: £35,000 to £40,000 (dependent on experience)


Contract Type: Full-time, Permanent


Reports to: Operations Manager


About the Role


UnifyHQ is proud to be working in partnership with our client, a leading energy efficiency provider delivering grant-funded retrofit solutions across South Wales. Their work spans solar PV, battery storage, air source heat pumps and insulation, with a strong focus on compliance, quality, and carbon reduction.


We are seeking a technically minded Renewables Design Specialist to lead the design, specification, and optimisation of low-carbon energy systems. This role supports domestic and commercial installations, ensuring all designs meet MCS standards, Building Regulations, and industry best practice.


Key Responsibilities



  • Produce detailed technical designs, schematics, and layout drawings for solar PV, battery storage, ASHP, and ventilation systems (PIV, dMEV)

  • Carry out load, yield, and performance calculations using specialist design software

  • Specify components and materials to ensure efficiency, quality, and cost-effectiveness

  • Prepare technical documentation for installation teams, subcontractors, and customers

  • Ensure compliance with MCS standards, BS 7671 wiring regulations, and manufacturer requirements

  • Conduct feasibility assessments and energy modelling based on site surveys, EPC data, and client needs

  • Ensure all designs and documentation meet PAS 2030/2035, TrustMark, MCS, and planning standards

  • Review and sign off commissioning documentation and as-built drawings

  • Collaborate with Project Managers, Retrofit Coordinators, and Installers to maintain design intent

  • Provide technical support and problem-solving during installation and commissioning


Candidate Profile



  • Minimum 3 years’ experience in renewable energy system design

  • Working knowledge of MCS, PAS 2035, and Building Regulations Part L

  • Proficiency in relevant design software

  • Strong understanding of electrical design principles and grid connection requirements (G98/G99)

  • Excellent communication skills and attention to technical detail

  • Ability to manage multiple projects and meet deadlines

  • Experience within retrofit or social housing decarbonisation programmes

  • Understanding of SAP, EPCs, and energy modelling methodologies


What’s on Offer



  • Company pension

  • Company vehicle for attending site visits

  • Mobile phone

  • Fast-paced and supportive team environment

  • Opportunity to help shape commercial growth in the renewables sector

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Posted: October 11th, 2026