Senior Residential Mechanical Designer

PEG, LLC • Fairfax, VA

4d • Hybrid

About The Position

PEG, LLC is a diverse energy efficiency, engineering, environmental, and management consulting firm operating principally in the Eastern and Central United States. The Senior Residential Mechanical Designer is a senior technical contributor responsible for the quality, efficiency, and technical excellence of residential HVAC design projects. The position influences project outcomes, improves design processes, supports code compliance, and advances high-performance and green building practices. It calls for technical leadership, independent decision-making, and mentoring and training team members in a collaborative, fast-paced environment.

The role is based in PEG’s main office in Fairfax, Virginia, with the option of a hybrid remote/office work schedule. The designer leads and reviews residential HVAC calculations and designs, supports project coordination and documentation, and works with internal teams and external stakeholders to resolve technical issues and meet project requirements. The role also contributes to internal standards and process improvements, staff development, and continuing professional development.

Requirements

• Bachelor of Science degree in Mechanical Engineering or a related field.
• At least 3 years of relevant experience in residential mechanical (HVAC) design.
• Advanced proficiency in AutoCAD.
• Advanced proficiency in HVAC load calculation.
• Advanced proficiency using WrightSoft or similar residential HVAC design software.
• Advanced understanding of ACCA Manual J, Manual D, and Manual S methodologies.
• Strong working knowledge of IECC, ENERGY STAR®, and state residential energy code requirements.
• Advanced proficiency in Excel and SharePoint.
• Strong attention to detail and accuracy.
• Ability to meet deadlines and manage multiple projects simultaneously.
• Efficient time management and organizational skills.
• Effective interpersonal and collaboration skills.
• Excellent verbal and written communication skills.
• Ability to read, write, and comprehend technical instructions and documentation.
• Strong analytical and problem-solving abilities.
• Ability to work independently with minimal oversight while supporting team development.

Nice To Haves

• EIT certification is strongly encouraged.
• Experience working with green building programs and high-performance residential construction.

Responsibilities

• Lead the preparation, review, and validation of HVAC load calculations, duct sizing, ventilation strategies, and equipment sizing in accordance with ACCA standards and applicable energy codes.
• Serve as a senior technical resource for the analysis and design teams.
• Conduct advanced QA/QC reviews of residential mechanical designs and energy modeling deliverables.
• Identify design, compliance, or workflow issues and communicate recommendations and resolution options to management.
• Manage complex project scopes by organizing deliverables, milestones, and priorities.
• Establish and maintain project timelines, adjusting schedules proactively as project demands and conditions change.
• Develop technical solutions and process workarounds to maintain project progress and quality standards.
• Coordinate and validate design relationships with internal departments, clients, builders, architects, and other project stakeholders.
• Interpret client requirements, jurisdictional constraints, and project-specific design considerations.
• Use and adapt to industry software platforms, including Manual J Software, AutoCAD, Wrightsoft/Wrightdraw, RESCheck, REM/Rate, and emerging technologies.
• Maintain and manage project documentation, calculations, and reporting through Excel, SharePoint, and internal systems.
• Interface with Operations, Owners, Builders, and Subcontractors to resolve technical issues and communicate project impacts.
• Maintain advanced knowledge of current IECC requirements, state energy codes, and residential mechanical design standards.
• Support the development and implementation of internal best practices, templates, and process improvements.
• Train and mentor junior and mid-level team members on technical procedures, software applications, code compliance, and company standards.
• Assist with onboarding and technical development initiatives for new staff.
• Participate in continuing education, certifications, and professional development related to residential HVAC design and green building practices.

Benefits

• 20 annual paid days off, comprising 12 days of PTO, birthday PTO, and 7 company-paid holidays.
• Company-sponsored medical insurance, with a contribution of up to 50% of the monthly premium.
• Dental and vision insurance.
• 401(k) retirement plan with up to a 4% company match, vested immediately.
• Basic life and supplemental life insurance.
• Short-term and long-term disability coverage.
• Accident and pet insurance.
• Corporate-sponsored events.
• Paid professional development and salary incentives through learning and certification opportunities.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior