Wilhelminenhofstraße 92, 12459 Berlin

030 - 509 69 48 7

 +49 157 7215 9125














Your one stop contact for
Interior Construction

About us

With more than 20 years of experience in the field of interior construction, Ralf Friedrich and Oliver Krüger have founded their own company “F+K Projektbau GmbH” in October 2017. In January 2024, Maxim Kremer joined the company as Commercial Managing Director and has since complemented the duo with his financial expertise, supporting the joint plans for further growth of F+K Projektbau GmbH.

As a company, we specialize in the Berlin/Brandenburg region in the complete renovation of apartments and houses, as well as trade-specific painting, drywall, plastering, and tiling works in both new construction and existing buildings.


Starting with just one employee, the two founders have since succeeded in building a loyal and satisfied client base while steadily expanding the team, which now consists of 42 permanent employees.

It has always been important to us that new team members not only fit professionally, but above all personally with one another and with us. Making a difference, creating real impact, and building the company sustainably with a long-term perspective for everyone involved — these are our priorities.


You want to know more about us, our philosophy and who’s behind F+K. Klick on About us and we are happy to introduce ourselves.

About usF+K Projektbau GmbH
(soon to be HAG Bauen)

Our ServiceInterior construction & more

Interior construction

Painter and wallpaper  hanging works

  • Customer orientated & individual shaping of walls and ceilings
  • Lacquer- and wood glaze works at windows, doors & stairs
  • Restoration according monument to protection guidelines
  • Processing of newly designed & traditional wall papers

Drywall installations

  • Consulting and implementation of room design concepts applying drywall systems
  • Acoustic protection as well as cove lighting installations
  • Drywall installations according fire prevention guidelines

Bricklaying & plastering works, plastering techniques

  • Construction of masonry walls
  • Creation and modification of door and window openings as part of renovation projects
  • Full-surface interior plastering in quality levels Q1–Q4
  • Custom and decorative plastering techniques, such as marble finishes
  • Facade treatment and finishing works 

Plumbering, Heating & Sanitary Installations

  • Installation and replacement of fresh water and wastewater pipes as part of apartment and house renovations
  • Minor repairs and replacement of sanitary fixtures and heating systems
  • Execution of riser pipe renovations

Tile installations

  • Individual bathroom and kitchen configuration
  • Balcony and terrace works
  • Mosaic and natural rock laying 
  • Tile installation from intricate mosaic tiles to large-format slabs

Roofing & Sheet Metal Works

  • Minor repairs to roof surfaces and tiled roofs
  • Waterproofing / filling works on roof areas and at transitions between the roof and adjoining building elements
  • Roof plumbing (sheet metal) works and repairs of drainage systems 

& more in cooperation with our partners

Carpenter- & floor laying works

  • Production of windows, doors and stairs including necessary glazier works
  • Restoration & repair works according to monument protection guidelines
  • Parquet, laminate, linoleum, PVC and carpet laying

Electrical Works

  • Complete electrical refurbishment as part of apartment and house renovations
  • Minor repairs within the scope of service and maintenance assignments
  • Expansion and upgrading of existing electrical systems in coordination with clients and project partners 

Construction supervison (up to large family houses or similar)

  • Planning and walkthrough of construction drawings & static / structural engineering calculations
  • Submission of building applications + administration of approval process
  • Project Management – and controlling incl. cost control for our customers
Our field of expertise
Services for our commercial customers

Implementation of single or complete packages out of our service portfolio for new and existing buildings up to 200 living units or 15.000 sqm.


  • Reconstruction of single flats
  • Implementation of large-scale contracts of single service activities out of our portfolio
  • New building erections & repair works

An extract of our contract partners

 
 
Services for our private households
  • Reconstruction, repair works & maintenance of properties incl. guidance and consultancy 
  • Interior construction for new erection of buildings
  • Optional: creation of construction plans & required static calculations for upcoming construction projects
What our customers are sayingGoogle ratings

Wir haben im Zeitraum 09/2018 bis 04/2019 eine sehr geräumige, freitragende Doppelgarage mit Nebengelass von ca. 60 m² durch die Firma F+K Projektbau errichten lassen.

Sa Pe
Our partners from our implementation partners up to qualified suppliers
Implementation partner
Ingenieurbürp Dipl.-Ing. M. Karioth
Andreas Riedel | Fliesen - Platten - Mosaik
Contact Let us implement new projects together.

You are welcome to use our contact form

F+K Projektbau GmbH

 Wilhelminenhofstraße 92, 12459 Berlin

030 - 509 69 48 7

info@fk-projektbau.de