We are committed to great design.

Modern hotel lobby with white walls, a patterned black and white floor, a marble reception desk, potted plants, an art piece, and a staircase leading upstairs.

The best projects come from builders and architects working as true partners.

  • Faithfully executed designs

  • Thoughtful collaboration and problem-solving

  • Reliable and transparent project budgets

  • Vetted process based on years of experience.

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Alex Harwin, M.Arch

Co-Founder

With a master’s degree in architecture and years of experience working in respected architectural firms, Alex brings a deep understanding of design and construction. He collaborates seamlessly with design teams, translating complex plans into built reality with precision and respect for intent. And as someone married to an architect, Alex’s life—both professionally and personally—is shaped by a commitment to thoughtful design.

Jason Jagentenfl

Co-Founder — 25+ Years in the Trades

Jason has led multimillion-dollar custom home projects across California and Greater Boston. His deep trades background and leadership on complex builds means scheduling, coordination, and quality control are never an afterthought — they're baked into how he works.

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Trusted by Leading Boston-Area Design Firms

Why Streamline

The best homes emerge from builders and architects working as true partners.

  • Co-founder Alex Harwin holds a master’s degree in architecture and spent five years working in architecture firms. That foundation enables us to navigate the most intricate, large-scale residential designs—partnering with top-tier architects to ensure every detail is executed without compromise.

  • Detailed estimates before we break ground. Monthly budget updates and bi-monthly invoices with full documentation and receipts — no surprises and an open book.

  • Regular client site meetings with clear agendas. Ongoing dialogue with your design team throughout every phase — we reach out, you don't have to chase us.

  • We’re continually learning and engaging with net-zero, Passivhaus, and Pretty Good House principles. We collaborate with building science experts to explore sustainable solutions tailored to each project.

  • We remain a resource long after project closeout — ensuring your clients' homes continue to perform and that your relationship with them stays protected.

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