Services
Four ways we engage on a project
From integrated design-build to working alongside your selected architect — we adjust to where you are. The four standard engagement models below cover most situations.
1. Design-build
Integrated architecture + construction
When to choose this
You don’t have an architect yet. Or you want speed. Or you have a complex project where architecture + construction need to evolve together throughout design. About 40% of our projects.
What you get
Hartwell architecture team designs the project from schematic through construction documents. Same studio builds it. Single contract. Faster path; more cohesive result.
Pricing model
Pre-construction services billed hourly during design phase (typically $80K–$300K total depending on project scope). GMP construction contract once design is complete.
Timeline impact
Compresses overall schedule by 3–5 months vs. separate architect + bid process. Particularly valuable on tight-timeline projects.
2. Builder for selected architect
We work alongside your architect
When to choose this
You have an architect already (or plan to engage one separately). You want a builder who can collaborate cleanly with the architect during design + construction. About 50% of our projects.
What you get
We come in as early as schematic design phase to inform constructability + cost. We handle pre-construction, permitting, and construction. Architect remains design lead throughout.
Architects we’ve worked with
Robert A.M. Stern Architects, Annabelle Selldorf, Tom Kundig, Allan Greenberg, Steven Harris, John Pawson — plus regional architects. We collaborate well with most.
Pricing model
Pre-construction services hourly during design phase (typically $50K–$200K). GMP construction contract once design is complete.
3. Construction-only
Build to completed construction documents
When to choose this
Construction documents are complete; you’re selecting the builder. We’re open to this engagement when the design quality is high + the project fits our practice. About 5% of our projects.
What you get
Pre-construction estimating, value engineering, permitting, construction. We don’t redesign mid-stream; we execute the documented intent.
Pricing model
Fixed-fee or GMP contract on completed CDs. Construction-cost transparency throughout.
When we'd decline
If we think the construction documents have material constructability or quality concerns. We’d rather decline than execute work we don’t believe in.
4. Pre-construction services only
Estimating + value engineering, design-phase advisory
When to choose this
Your architect is selected. You want a builder advising on cost + constructability before you commit. We’ll do this even if we’re not eventually selected to build.
What you get
Cost estimates at each design milestone, value-engineering options, constructability review, schedule modeling, supply-chain risk identification.
Pricing model
Hourly + flat-fee mix. Typical engagement: $35K–$80K total across the design phase. No commitment to use Hartwell as builder afterward.
When this is the right call
Often when budget alignment is uncertain + you want a clear-eyed cost picture before committing to design direction.
Specialty + smaller scope services
What else we do
ADUs + carriage houses
$500K – $2M scope. Often standalone projects, sometimes the start of larger relationships. Same studio, scaled-down delivery model.
Historic restoration
Federal-style, Greek Revival, Shingle Style, Colonial Revival — we have specific experience with each. Section 106 historic review, NPS Historic Tax Credit consulting available.
Net-zero + Passive House
We have completed PHIUS-certified projects + net-zero-energy projects. Geothermal, structural insulation, building-envelope-first design.
Maritime + coastal-resilient
Coastal Maine + Cape + Islands work. Storm-resilient structural engineering, FEMA flood-zone compliance, salt-environment material selection.
Multi-generational + estate planning
Several active projects involve multi-decade thinking — mother-in-law suites, future-proofing for aging-in-place, multi-generational compounds. We bring patience to these conversations.
Stewardship + maintenance
Past clients receive ongoing stewardship. Annual walkthroughs, repair coordination, system maintenance. Often-overlooked aspect of building expensive houses.
Service questions
What people ask
- Most projects are $2M – $8M total construction cost. We’ll consider $500K–$2M for specialty smaller scopes (ADUs, carriage houses) and over $8M for estate-grade work. Below $500K, we typically refer to peer builders.