Senior Residential Mechanical Designer

Jobless; Fairfax (VA); Hybrid; USD 100,000 - 130,000; Full time

Benefits offered by this job

Medical Insurance

401(k) with company match

Paid time off

Professional development

Job summary

PEG LLC, a trusted energy‑efficiency and environmental consulting firm, seeks a Senior Residential Mechanical Designer in Fairfax, VA with a hybrid remote/office option. You will lead HVAC design activities, validate calculations, and mentor a project team to ensure high performance and compliance with IECC and ACCA standards.

The role emphasizes technical leadership, collaboration with builders/architects, and a focus on sustainable, green building practices within a fast-paced environment.

Qualifications

• BS in Mechanical Engineering or related field is required.
• 3+ years of experience in Residential Mechanical (HVAC) Design.
• Advanced proficiency in AutoCAD.
• Advanced proficiency in HVAC load calculations.
• Advanced proficiency using WrightSoft or similar residential HVAC design software.
• Solid understanding of ACCA Manual J, D, S methodologies.
• Strong knowledge of IECC, ENERGY STAR, and state energy codes.

Responsibilities

• Lead HVAC load calculations, duct sizing, ventilation strategies, and equipment sizing per ACCA Standards.
• Serve as senior technical resource for analysis and design teams.
• Perform QA/QC reviews of residential designs and energy modeling deliverables.
• Manage project scopes with timelines and priorities.
• Mentor junior team members and support onboarding.

Skills

AutoCAD

Manual J

Wrightsoft

Energy codes

Project leadership

Education

BS Mechanical Engineering

EIT encouraged

Tools

Manual J Software

Wrightsoft/Wrightdraw

RESCheck

REM/Rate

Excel

SharePoint

Job description

PEG, LLC is in its twenty-eighth year being a diverse energy efficiency, engineering, environmental and management consulting firm operating principally in the Eastern and Central United States.

PEG, LLC is proud to partner with many of the nation’s leading homebuilders in delivering construction compliance services. As a leader in Home Energy Ratings, a winner of multiple Energy Star Awards, and a standout in the construction industry, PEG has provided Home Energy Ratings for over 250,000 homes. Our mission is to deliver innovative, data-driven solutions that support high-performance buildings, sustainable development, and client success across residential and commercial sectors. We strive to continually improve building energy efficiency and therefore, the quality of homes and life in the communities that we service.

Please visit our website at www.pegenv.com to learn more about PEG!

WHO ARE YOU?

Senior Residential Mechanical Designers at PEG play a critical role in driving the quality, efficiency, and technical excellence of residential HVAC design projects. This position serves as a senior technical contributor responsible for influencing project outcomes, improving design processes, supporting code compliance, and advancing PEG’s commitment to high-performance and green building practices. Through advanced expertise in residential mechanical design, this role directly impacts project accuracy, client satisfaction, operational efficiency, and overall team development.

This senior-level position is intended for experienced professionals who demonstrate strong technical leadership, independent decision-making, and the ability to mentor and train team members. PEG specializes in sustainable and energy-efficient residential design, and this role is instrumental in ensuring projects consistently meet the highest standards of performance, compliance, and innovation. We are seeking a self-motivated, detail-oriented, and solution-driven professional who thrives in a collaborative and fast-paced environment.

THE ROLE

Job Location:

This position is based in our main office in Fairfax, VA with the option of a hybrid remote/office work schedule.

Essential Functions

• 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
• Perform 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 project priorities
• Establish and maintain project timelines while proactively adjusting schedules based on project demands and changing conditions
• 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
• Utilize and adapt to industry software platforms including Manual J Software, AutoCAD, Wrightsoft/Wrightdraw, RESCheck, REM/Rate, and other 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 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.

Education/Experience

• B.S. Degree in Mechanical Engineering or related field is required
• EIT is strongly encouraged. A salary incentive will be offered to those who obtain it.
• Minimum 3+ years of relevant experience in Residential Mechanical (HVAC) Design required;
• Advanced proficiency in AutoCAD experience required
• Advanced proficiency in HVAC load calculation experience required
• Advanced proficiency using WrightSoft or similar residential HVAC design software required
• 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
• Experience working with green building programs and high-performance residential construction preferred

Additional Requirements

• Advanced proficiency in Excel and SharePoint
• Strong attention to detail and accuracy
• Deadline-oriented with the ability to 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

Rewards and Benefits

PEG LLC offers a comprehensive, total rewards package that includes competitive compensation and a flexible benefits package that reflects our commitment to creating a diverse and supportive workplace.

• 20 Annual Paid Days Off (12 Days of PTO, Birthday PTO, & 7 Company Paid Holidays)
• Company Sponsored Medical Insurance that includes a contribution of up to 50% off the monthly premium
• Dental & Vision Insurance
• 401(k) Retirement Plan with up to a 4% company match vested immediately
• Basic Life & Supplemental Life
• Short-Term & Long-Term Disability
• Accident & Pet Insurance
• Corporate Sponsored Events
• Paid Professional Development & Salary Incentives through Learning/Certification Opportunities

PEG LLC is an Equal Employment Opportunity Employer.

PEG, LLC uses E-Verify to confirm the identity and employment eligibility of all new hires.