Apartment Renovations: Comprehensive Guide with BIM Model and Design Steps

AEC businesses are becoming increasingly involved into renovation projects rather than in new construction.

In this article we’ll be dealing with the project phases of an apartment renovation process, presenting a practical case with a 3D BIM model to download, along with a video showing how to carry out a renovation project with a BIM architectural design software and some keynote slides.

Render of the existing conditions of the entrance area

Project Render of the entrance area produced with Edificius

Types of apartment renovations and definitions

There are various types of intervention, especially when it comes to an apartment renovation.
Let’s see them in detail:

1. “ordinary maintenance interventions“ are building interventions regarding repair, renovation and finishes replacement together with works necessary to integrate and maintain existing plant installations;
2. “extraordinary maintenance interventions“ are works necessary to renovate and replace structural parts of buildings, as well as to integrate sanitation and technological services provided that it does not alternate the overall volume of the building. Among the ordinary maintenance interventions the dividing and merging of building units are also contemplated;
3. “conservation and restoration of cultural heritage“ focuses on building interventions aimed at preserving the property unit and ensuring its functionality. These interventions include consolidation, restoration and renewal of the building’s constituent elements, inserting accessory elements and plant installations according to specific needs or the elimination of elements that are not part of the building;
4. “building renovation“ involves interventions tha aim at, entirely or partially, transforming existing real estate units. These interventions include the restoration or replacement of some building elements, by removing, modifying and inserting new elements and installations. This process might also include demolition and reconstruction interventions.

Therefore, an intervention that modifies the distribution and architectural structure of an internal environment can be considered:

• extraordinary light maintenance, if it involves the replacement of existing non-structural elements
• heavy extraordinary maintenance, if it involves the replacement of existing elements, including structural ones
• light building renovation, if new elements and systems are to be installed.

In short, the difference between building renovation and extraordinary maintenance is essentially the addition of new elements. In fact, restructuring can be considered as a series of works to transform the building with the aim of improving or modernising an old, damaged or defective building.

Read the article: “Emergency maintenance: what it is, types and examples“.

Building renovation and authorizations

Once the correct type of renovation has been identified, legal and regulatory authorizations are generally required to proceed with the start of works.

Each country adopts different types of procedures and documentation to be produced in order to obtain these authorizations.

Render of the existing condition of a kitchen

Project render of a kitchen produced with Edificius

Key Design Phases in an Apartment Renovation Project

An apartment renovation project includes different phases and interventions connected to each other within the unitary project. The first phase involves site inspection and an accurate survey, with verification of the state of the main plant installations (water, thermal, electrical). At this stage project drawings are produced.

Subsequently, according to the indications and requests of the client, the apartment is redesigned for functional and architectural purposes. During the progress of the three different project phases (preliminary, definitive and executive), the necessary elements are created for drafting a cost estimate and obtain the financial assessment of the entire intervention.

Finally, after proceeding with the choice of materials to be used for renovation (cladding, flooring, painting, etc.) construction works begin.

Consequently, the various phases of the design process for any type of intervention include:

1. Inspection
2. Data and area view retrieval, approved projects
3. Metric, material and photographic survey of the state of sites
4. Preparation of the preliminary project
5. Final / executive project processing
6. Preparation of the documentation required to obtain approvals

Apartment renovation project cost

To estimate the complete cost of an apartment renovation project, it is necessary to prepare a detailed cost estimating that associates the work to be performed to the relative quantities and unit costs. The generic structure of a cost estimate can be articulated as follows:

• Removals: doors, windows, shutters, heating elements, sanitary appliances, etc.;
• Demolitions: floor, screed, cladding, partitions, false ceilings, etc.;
• Handling of material from demolitions and transportation to an authorized landfill;
• Construction of new plant installations, new partitions, screeds, floors, claddings, plasters, false ceilings, painting;
• Supply and installation of sanitary equipment, doors and fixtures

In the next focus insights we will provide in-depth information on the methodology to use  in order to produce cost estimating by analyzing an apartment renovation project as a case study and providing a practical example to download.

Benefits of Using BIM for Apartment Renovations

By creating highly detailed 3D models, BIM allows for a thorough analysis of the existing conditions of the apartment, simulating different design options. This process helps identify structural or technical problems in advance, significantly reducing design errors, unexpected costs, and downtime on site.

One of the greatest benefits of BIM is design efficiency. The ability to virtually visualize every detail of the intervention enables designers to optimize space utilization, simulate energy performance, and test various aesthetic or functional solutions before moving to the operational phase. This not only reduces the risk of late changes but also ensures results that align with client expectations.

Collaboration among various stakeholders is another key point. Through a shared platform, architects, engineers, contractors, and owners can access the same digital model, communicate in real-time, and make informed decisions. Thanks to features like role-based access, each team member can focus on information relevant to their field, avoiding misunderstandings and improving the overall efficiency of the project.

Another central aspect is cost and time reduction. With BIM, it is possible to optimize resources, reduce material waste, and prevent conflicts between systems and structures through clash detection.

From a sustainability standpoint, BIM stands out for its ability to integrate advanced energy analyses. Through simulations of thermal and lighting performance, designers can propose eco-friendly solutions, such as efficient insulation systems or the use of recycled materials, reducing the environmental impact of the intervention. Furthermore, these analyses enhance residential comfort, maximize energy efficiency, and lower future operating costs.

An additional value of BIM is lifecycle management. The digital model doesn’t end with the completion of the work but becomes a living archive of the project, containing useful information for maintenance, repairs, and future modifications. This approach ensures more sustainable and strategic long-term property management.

Finally, BIM offers advanced visualization tools, such as augmented reality and virtual tours, allowing clients to fully understand the final result of the renovation before work even begins. The ability to virtually explore the renovated apartment, viewing materials, colors, and design details, not only facilitates the decision-making process but also increases client satisfaction and reduces the risk of misunderstandings.

To learn more, read also: How to design a two-room apartment: the complete technical guide

Apartment renovation project: a practical case

Apartament renovation project: aerial render of the existing condition

Top view render of the apartment project produced with Edificius

In this section we’ll be analyzing the functional and architectural transformation of an apartment built during the 60s-70s that presents the typical spaces distribution designed around a long central hall. The entrance to the living unit opens directly on the shorter side of the central hall. On the left side you can access to the kitchen and kitchenette, then to the bathroom and the bedroom. On the opposite side you can access the living room, dining room and a second bedroom. Each environment is functionally independent from the other.

Render existing conditions of the living area

Project Render living room produced with Edificius

The objective of the project is to design a space in line with the current housing needs of an average family. For this reason, the living area has been completely redesigned by creating a single space that includes a living room and a dining area. The eat-in kitchen is connected to the open space through large glass sliding doors that allow greater privacy when needed. The hall is thus reduced to the minimum and equipped with hangers and bookcases to optimize spaces. The sleeping area, separated from the living area, preserves the original bedrooms unaltered, enhanced by the addition of service areas such as the walk-in closet and private bathroom.

This case is an example of building renovation, as it is planned to add installations ex novo that don’t exist at the current situation.

Apartment renovation project with DWGs

Below, you can find available for download, project drawings (floor plans and sections) and the 3D model of an apartment renovation example.

Download the project 3D BIM model (.edf file)