Hartwell&Kessler

An architecture and interiors studio designing calm, lasting homes.

Modern pavilion with floor-to-ceiling glass walls overlooking a rectangular reflective pool at dusk, featuring an outdoor patio with stone flooring and visible interior dining and living areas warmly lit.

Project 04 — Casa Lume, 2025

Studio
[01]

Architecture and interiors, designed as one.

Founded in 2012, the studio works on private houses and renovations worldwide, with architects and interior designers under one roof.

Founded
2012
Completed projects
140+
Countries
12
Awards & publications
24

We design houses and their interiors as one continuous thought — from the first line drawn on site to the last handle on a cabinet door.

Architecture
Interiors
Residential
Renovation
Furniture
Landscape
Architecture
Interiors
Residential
Renovation
Furniture
Landscape
Selected work
[02]

Houses shaped by their site, and by the people who live in them.

All projects

Approach

[03]

From first visit to the keys in your hand.

Every project follows the same five stages, led by one team from start to finish.

No.

Stage

Deliverables

Duration

Team

01

Site & brief

Listening first

Site survey, written brief

2–4 weeks

Architect, interior designer

We walk the site with you and write down how you want to live, before anything is drawn.

02

Concept

First ideas

Sketches, models, cost estimate

4–6 weeks

Architect, interior designer

Sketches, models and a first idea of light, materials and cost.

03

Design & permits

Drawn in detail

Drawings, planning application

3–6 months

Architects, engineers

The full design of house and interiors, drawn in detail and taken through planning.

04

Build

On site

Site visits, cost control

12–18 months

Project architect, builders

We stay on site with the builders, solving the questions drawings can't answer.

05

Handover

Ready to live in

Furniture, lighting, styling

4–6 weeks

Interior designer, stylist

Furniture, lighting and the last details in place, then the keys are yours.

Testimonials

[04]

Judged by the people who live in them.

A few words from clients, written after they moved in.

01

Stone House, 2025

“They listened for three months before drawing a single line. The house we live in now feels like it was always meant to be on that hillside.”

Clara & Jonas Weber

Owners

02

Pavilion House, 2024

“Every detail was resolved on paper before it reached the site. We finished on budget, two weeks early, and never had to chase anyone for an answer.”

Daniel Reyes

Owner

03

Terrace House, 2024

“The interiors carry the same calm as the architecture. Nothing is there for show, and everything we touch every day feels considered.”

Elena Marsh

Owner

04

Harbour Apartment, 2023

“The studio turned an awkward apartment into the best rooms we have ever lived in. The light alone was worth it.”

Laura Bennett

Owner

05

Hale Gallery, 2023

“One team from first sketch to final handover. That continuity is rare, and it shows in every junction of the building.”

Marcus Hale

Director